Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
72 | #include <linux/sched.h> | |
73 | #include <linux/interrupt.h> | |
74 | #include <linux/tty.h> | |
75 | #include <linux/tty_driver.h> | |
76 | #include <linux/tty_flip.h> | |
77 | #include <linux/devpts_fs.h> | |
78 | #include <linux/file.h> | |
9f3acc31 | 79 | #include <linux/fdtable.h> |
1da177e4 LT |
80 | #include <linux/console.h> |
81 | #include <linux/timer.h> | |
82 | #include <linux/ctype.h> | |
83 | #include <linux/kd.h> | |
84 | #include <linux/mm.h> | |
85 | #include <linux/string.h> | |
86 | #include <linux/slab.h> | |
87 | #include <linux/poll.h> | |
88 | #include <linux/proc_fs.h> | |
89 | #include <linux/init.h> | |
90 | #include <linux/module.h> | |
1da177e4 | 91 | #include <linux/device.h> |
1da177e4 LT |
92 | #include <linux/wait.h> |
93 | #include <linux/bitops.h> | |
b20f3ae5 | 94 | #include <linux/delay.h> |
a352def2 | 95 | #include <linux/seq_file.h> |
d281da7f | 96 | #include <linux/serial.h> |
5a3c6b25 | 97 | #include <linux/ratelimit.h> |
1da177e4 | 98 | |
a352def2 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | |
101 | #include <linux/kbd_kern.h> | |
102 | #include <linux/vt_kern.h> | |
103 | #include <linux/selection.h> | |
1da177e4 LT |
104 | |
105 | #include <linux/kmod.h> | |
b488893a | 106 | #include <linux/nsproxy.h> |
1da177e4 LT |
107 | |
108 | #undef TTY_DEBUG_HANGUP | |
109 | ||
110 | #define TTY_PARANOIA_CHECK 1 | |
111 | #define CHECK_TTY_COUNT 1 | |
112 | ||
edc6afc5 | 113 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
114 | .c_iflag = ICRNL | IXON, |
115 | .c_oflag = OPOST | ONLCR, | |
116 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
117 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
118 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
119 | .c_cc = INIT_C_CC, |
120 | .c_ispeed = 38400, | |
121 | .c_ospeed = 38400 | |
1da177e4 LT |
122 | }; |
123 | ||
124 | EXPORT_SYMBOL(tty_std_termios); | |
125 | ||
126 | /* This list gets poked at by procfs and various bits of boot up code. This | |
127 | could do with some rationalisation such as pulling the tty proc function | |
128 | into this file */ | |
37bdfb07 | 129 | |
1da177e4 LT |
130 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
131 | ||
24ec839c | 132 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 133 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 134 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 135 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 136 | |
ee2ffa0d NP |
137 | /* Spinlock to protect the tty->tty_files list */ |
138 | DEFINE_SPINLOCK(tty_files_lock); | |
139 | ||
1da177e4 LT |
140 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
141 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
142 | ssize_t redirected_tty_write(struct file *, const char __user *, |
143 | size_t, loff_t *); | |
1da177e4 LT |
144 | static unsigned int tty_poll(struct file *, poll_table *); |
145 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 146 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 147 | #ifdef CONFIG_COMPAT |
37bdfb07 | 148 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
149 | unsigned long arg); |
150 | #else | |
151 | #define tty_compat_ioctl NULL | |
152 | #endif | |
ec79d605 | 153 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 154 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 155 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 156 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 157 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 158 | |
af9b897e AC |
159 | /** |
160 | * free_tty_struct - free a disused tty | |
161 | * @tty: tty struct to free | |
162 | * | |
163 | * Free the write buffers, tty queue and tty memory itself. | |
164 | * | |
165 | * Locking: none. Must be called after tty is definitely unused | |
166 | */ | |
167 | ||
bf970ee4 | 168 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 169 | { |
dc6802a7 DC |
170 | if (!tty) |
171 | return; | |
30004ac9 DES |
172 | if (tty->dev) |
173 | put_device(tty->dev); | |
1da177e4 | 174 | kfree(tty->write_buf); |
89c8d91e | 175 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
176 | kfree(tty); |
177 | } | |
178 | ||
d996b62a NP |
179 | static inline struct tty_struct *file_tty(struct file *file) |
180 | { | |
181 | return ((struct tty_file_private *)file->private_data)->tty; | |
182 | } | |
183 | ||
fa90e1c9 | 184 | int tty_alloc_file(struct file *file) |
d996b62a NP |
185 | { |
186 | struct tty_file_private *priv; | |
187 | ||
f573bd17 PE |
188 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
189 | if (!priv) | |
190 | return -ENOMEM; | |
d996b62a | 191 | |
fa90e1c9 JS |
192 | file->private_data = priv; |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
197 | /* Associate a new file with the tty structure */ | |
198 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
199 | { | |
200 | struct tty_file_private *priv = file->private_data; | |
201 | ||
d996b62a NP |
202 | priv->tty = tty; |
203 | priv->file = file; | |
d996b62a NP |
204 | |
205 | spin_lock(&tty_files_lock); | |
206 | list_add(&priv->list, &tty->tty_files); | |
207 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 208 | } |
f573bd17 | 209 | |
fa90e1c9 JS |
210 | /** |
211 | * tty_free_file - free file->private_data | |
212 | * | |
213 | * This shall be used only for fail path handling when tty_add_file was not | |
214 | * called yet. | |
215 | */ | |
216 | void tty_free_file(struct file *file) | |
217 | { | |
218 | struct tty_file_private *priv = file->private_data; | |
219 | ||
220 | file->private_data = NULL; | |
221 | kfree(priv); | |
d996b62a NP |
222 | } |
223 | ||
224 | /* Delete file from its tty */ | |
2520e274 | 225 | static void tty_del_file(struct file *file) |
d996b62a NP |
226 | { |
227 | struct tty_file_private *priv = file->private_data; | |
228 | ||
229 | spin_lock(&tty_files_lock); | |
230 | list_del(&priv->list); | |
231 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 232 | tty_free_file(file); |
d996b62a NP |
233 | } |
234 | ||
235 | ||
1da177e4 LT |
236 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
237 | ||
af9b897e AC |
238 | /** |
239 | * tty_name - return tty naming | |
240 | * @tty: tty structure | |
241 | * @buf: buffer for output | |
242 | * | |
243 | * Convert a tty structure into a name. The name reflects the kernel | |
244 | * naming policy and if udev is in use may not reflect user space | |
245 | * | |
246 | * Locking: none | |
247 | */ | |
248 | ||
1da177e4 LT |
249 | char *tty_name(struct tty_struct *tty, char *buf) |
250 | { | |
251 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
252 | strcpy(buf, "NULL tty"); | |
253 | else | |
254 | strcpy(buf, tty->name); | |
255 | return buf; | |
256 | } | |
257 | ||
258 | EXPORT_SYMBOL(tty_name); | |
259 | ||
d769a669 | 260 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
261 | const char *routine) |
262 | { | |
263 | #ifdef TTY_PARANOIA_CHECK | |
264 | if (!tty) { | |
265 | printk(KERN_WARNING | |
266 | "null TTY for (%d:%d) in %s\n", | |
267 | imajor(inode), iminor(inode), routine); | |
268 | return 1; | |
269 | } | |
270 | if (tty->magic != TTY_MAGIC) { | |
271 | printk(KERN_WARNING | |
272 | "bad magic number for tty struct (%d:%d) in %s\n", | |
273 | imajor(inode), iminor(inode), routine); | |
274 | return 1; | |
275 | } | |
276 | #endif | |
277 | return 0; | |
278 | } | |
279 | ||
280 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
281 | { | |
282 | #ifdef CHECK_TTY_COUNT | |
283 | struct list_head *p; | |
284 | int count = 0; | |
37bdfb07 | 285 | |
ee2ffa0d | 286 | spin_lock(&tty_files_lock); |
1da177e4 LT |
287 | list_for_each(p, &tty->tty_files) { |
288 | count++; | |
289 | } | |
ee2ffa0d | 290 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
291 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
292 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
293 | tty->link && tty->link->count) | |
294 | count++; | |
295 | if (tty->count != count) { | |
296 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
297 | "!= #fd's(%d) in %s\n", | |
298 | tty->name, tty->count, count, routine); | |
299 | return count; | |
24ec839c | 300 | } |
1da177e4 LT |
301 | #endif |
302 | return 0; | |
303 | } | |
304 | ||
af9b897e AC |
305 | /** |
306 | * get_tty_driver - find device of a tty | |
307 | * @dev_t: device identifier | |
308 | * @index: returns the index of the tty | |
309 | * | |
310 | * This routine returns a tty driver structure, given a device number | |
311 | * and also passes back the index number. | |
312 | * | |
313 | * Locking: caller must hold tty_mutex | |
1da177e4 | 314 | */ |
af9b897e | 315 | |
1da177e4 LT |
316 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
317 | { | |
318 | struct tty_driver *p; | |
319 | ||
320 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
321 | dev_t base = MKDEV(p->major, p->minor_start); | |
322 | if (device < base || device >= base + p->num) | |
323 | continue; | |
324 | *index = device - base; | |
7d7b93c1 | 325 | return tty_driver_kref_get(p); |
1da177e4 LT |
326 | } |
327 | return NULL; | |
328 | } | |
329 | ||
f2d937f3 JW |
330 | #ifdef CONFIG_CONSOLE_POLL |
331 | ||
332 | /** | |
333 | * tty_find_polling_driver - find device of a polled tty | |
334 | * @name: name string to match | |
335 | * @line: pointer to resulting tty line nr | |
336 | * | |
337 | * This routine returns a tty driver structure, given a name | |
338 | * and the condition that the tty driver is capable of polled | |
339 | * operation. | |
340 | */ | |
341 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
342 | { | |
343 | struct tty_driver *p, *res = NULL; | |
344 | int tty_line = 0; | |
0dca0fd2 | 345 | int len; |
5f0878ac | 346 | char *str, *stp; |
f2d937f3 | 347 | |
0dca0fd2 JW |
348 | for (str = name; *str; str++) |
349 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
350 | break; | |
351 | if (!*str) | |
352 | return NULL; | |
353 | ||
354 | len = str - name; | |
355 | tty_line = simple_strtoul(str, &str, 10); | |
356 | ||
f2d937f3 JW |
357 | mutex_lock(&tty_mutex); |
358 | /* Search through the tty devices to look for a match */ | |
359 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
360 | if (strncmp(name, p->name, len) != 0) |
361 | continue; | |
5f0878ac AC |
362 | stp = str; |
363 | if (*stp == ',') | |
364 | stp++; | |
365 | if (*stp == '\0') | |
366 | stp = NULL; | |
f2d937f3 | 367 | |
6eb68d6f | 368 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 369 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 370 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
371 | *line = tty_line; |
372 | break; | |
373 | } | |
374 | } | |
375 | mutex_unlock(&tty_mutex); | |
376 | ||
377 | return res; | |
378 | } | |
379 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
380 | #endif | |
381 | ||
af9b897e AC |
382 | /** |
383 | * tty_check_change - check for POSIX terminal changes | |
384 | * @tty: tty to check | |
385 | * | |
386 | * If we try to write to, or set the state of, a terminal and we're | |
387 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
388 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
389 | * | |
978e595f | 390 | * Locking: ctrl_lock |
1da177e4 | 391 | */ |
af9b897e | 392 | |
37bdfb07 | 393 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 394 | { |
47f86834 AC |
395 | unsigned long flags; |
396 | int ret = 0; | |
397 | ||
1da177e4 LT |
398 | if (current->signal->tty != tty) |
399 | return 0; | |
47f86834 AC |
400 | |
401 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
402 | ||
ab521dc0 EB |
403 | if (!tty->pgrp) { |
404 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 405 | goto out_unlock; |
1da177e4 | 406 | } |
ab521dc0 | 407 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
408 | goto out_unlock; |
409 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 410 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
411 | goto out; |
412 | if (is_current_pgrp_orphaned()) { | |
413 | ret = -EIO; | |
414 | goto out; | |
415 | } | |
040b6362 ON |
416 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
417 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
418 | ret = -ERESTARTSYS; |
419 | out: | |
9ffee4cb AM |
420 | return ret; |
421 | out_unlock: | |
47f86834 AC |
422 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
423 | return ret; | |
1da177e4 LT |
424 | } |
425 | ||
426 | EXPORT_SYMBOL(tty_check_change); | |
427 | ||
37bdfb07 | 428 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
429 | size_t count, loff_t *ppos) |
430 | { | |
431 | return 0; | |
432 | } | |
433 | ||
37bdfb07 | 434 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
435 | size_t count, loff_t *ppos) |
436 | { | |
437 | return -EIO; | |
438 | } | |
439 | ||
440 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 441 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
442 | { |
443 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
444 | } | |
445 | ||
04f378b1 AC |
446 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
447 | unsigned long arg) | |
38ad2ed0 PF |
448 | { |
449 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
450 | } | |
451 | ||
37bdfb07 | 452 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 453 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
454 | { |
455 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
456 | } | |
457 | ||
62322d25 | 458 | static const struct file_operations tty_fops = { |
1da177e4 LT |
459 | .llseek = no_llseek, |
460 | .read = tty_read, | |
461 | .write = tty_write, | |
462 | .poll = tty_poll, | |
04f378b1 | 463 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 464 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
465 | .open = tty_open, |
466 | .release = tty_release, | |
467 | .fasync = tty_fasync, | |
468 | }; | |
469 | ||
62322d25 | 470 | static const struct file_operations console_fops = { |
1da177e4 LT |
471 | .llseek = no_llseek, |
472 | .read = tty_read, | |
473 | .write = redirected_tty_write, | |
474 | .poll = tty_poll, | |
04f378b1 | 475 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 476 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
477 | .open = tty_open, |
478 | .release = tty_release, | |
479 | .fasync = tty_fasync, | |
480 | }; | |
481 | ||
62322d25 | 482 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
483 | .llseek = no_llseek, |
484 | .read = hung_up_tty_read, | |
485 | .write = hung_up_tty_write, | |
486 | .poll = hung_up_tty_poll, | |
04f378b1 | 487 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 488 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
489 | .release = tty_release, |
490 | }; | |
491 | ||
492 | static DEFINE_SPINLOCK(redirect_lock); | |
493 | static struct file *redirect; | |
494 | ||
495 | /** | |
496 | * tty_wakeup - request more data | |
497 | * @tty: terminal | |
498 | * | |
499 | * Internal and external helper for wakeups of tty. This function | |
500 | * informs the line discipline if present that the driver is ready | |
501 | * to receive more output data. | |
502 | */ | |
37bdfb07 | 503 | |
1da177e4 LT |
504 | void tty_wakeup(struct tty_struct *tty) |
505 | { | |
506 | struct tty_ldisc *ld; | |
37bdfb07 | 507 | |
1da177e4 LT |
508 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
509 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 510 | if (ld) { |
a352def2 AC |
511 | if (ld->ops->write_wakeup) |
512 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
513 | tty_ldisc_deref(ld); |
514 | } | |
515 | } | |
4b19449d | 516 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
517 | } |
518 | ||
519 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
520 | ||
ea648a47 PH |
521 | /** |
522 | * tty_signal_session_leader - sends SIGHUP to session leader | |
f91e2590 PH |
523 | * @tty controlling tty |
524 | * @exit_session if non-zero, signal all foreground group processes | |
ea648a47 | 525 | * |
f91e2590 PH |
526 | * Send SIGHUP and SIGCONT to the session leader and its process group. |
527 | * Optionally, signal all processes in the foreground process group. | |
ea648a47 PH |
528 | * |
529 | * Returns the number of processes in the session with this tty | |
530 | * as their controlling terminal. This value is used to drop | |
531 | * tty references for those processes. | |
532 | */ | |
f91e2590 | 533 | static int tty_signal_session_leader(struct tty_struct *tty, int exit_session) |
ea648a47 PH |
534 | { |
535 | struct task_struct *p; | |
ea648a47 | 536 | int refs = 0; |
f91e2590 | 537 | struct pid *tty_pgrp = NULL; |
ea648a47 PH |
538 | |
539 | read_lock(&tasklist_lock); | |
540 | if (tty->session) { | |
541 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
542 | spin_lock_irq(&p->sighand->siglock); | |
543 | if (p->signal->tty == tty) { | |
544 | p->signal->tty = NULL; | |
545 | /* We defer the dereferences outside fo | |
546 | the tasklist lock */ | |
547 | refs++; | |
548 | } | |
549 | if (!p->signal->leader) { | |
550 | spin_unlock_irq(&p->sighand->siglock); | |
551 | continue; | |
552 | } | |
553 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
554 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
555 | put_pid(p->signal->tty_old_pgrp); /* A noop */ | |
bc30c3b2 | 556 | spin_lock(&tty->ctrl_lock); |
f91e2590 | 557 | tty_pgrp = get_pid(tty->pgrp); |
ea648a47 PH |
558 | if (tty->pgrp) |
559 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
bc30c3b2 | 560 | spin_unlock(&tty->ctrl_lock); |
ea648a47 PH |
561 | spin_unlock_irq(&p->sighand->siglock); |
562 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); | |
563 | } | |
564 | read_unlock(&tasklist_lock); | |
565 | ||
f91e2590 PH |
566 | if (tty_pgrp) { |
567 | if (exit_session) | |
568 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
569 | put_pid(tty_pgrp); | |
570 | } | |
571 | ||
ea648a47 PH |
572 | return refs; |
573 | } | |
574 | ||
af9b897e | 575 | /** |
11dbf203 | 576 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 577 | * @work: tty device |
af9b897e | 578 | * |
ef4f527c | 579 | * This can be called by a "kworker" kernel thread. That is process |
af9b897e AC |
580 | * synchronous but doesn't hold any locks, so we need to make sure we |
581 | * have the appropriate locks for what we're doing. | |
582 | * | |
583 | * The hangup event clears any pending redirections onto the hung up | |
584 | * device. It ensures future writes will error and it does the needed | |
585 | * line discipline hangup and signal delivery. The tty object itself | |
586 | * remains intact. | |
587 | * | |
588 | * Locking: | |
ec79d605 | 589 | * BTM |
24ec839c PZ |
590 | * redirect lock for undoing redirection |
591 | * file list lock for manipulating list of ttys | |
137084bb | 592 | * tty_ldiscs_lock from called functions |
6a1c0680 | 593 | * termios_rwsem resetting termios data |
24ec839c PZ |
594 | * tasklist_lock to walk task list for hangup event |
595 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 596 | */ |
f91e2590 | 597 | static void __tty_hangup(struct tty_struct *tty, int exit_session) |
1da177e4 | 598 | { |
37bdfb07 | 599 | struct file *cons_filp = NULL; |
1da177e4 | 600 | struct file *filp, *f = NULL; |
d996b62a | 601 | struct tty_file_private *priv; |
1da177e4 | 602 | int closecount = 0, n; |
ea648a47 | 603 | int refs; |
1da177e4 LT |
604 | |
605 | if (!tty) | |
606 | return; | |
607 | ||
1da177e4 LT |
608 | |
609 | spin_lock(&redirect_lock); | |
d996b62a | 610 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
611 | f = redirect; |
612 | redirect = NULL; | |
613 | } | |
614 | spin_unlock(&redirect_lock); | |
37bdfb07 | 615 | |
89c8d91e | 616 | tty_lock(tty); |
11dbf203 | 617 | |
cb50e523 PH |
618 | if (test_bit(TTY_HUPPED, &tty->flags)) { |
619 | tty_unlock(tty); | |
620 | return; | |
621 | } | |
622 | ||
acfa747b JS |
623 | /* some functions below drop BTM, so we need this bit */ |
624 | set_bit(TTY_HUPPING, &tty->flags); | |
625 | ||
ec79d605 AB |
626 | /* inuse_filps is protected by the single tty lock, |
627 | this really needs to change if we want to flush the | |
628 | workqueue with the lock held */ | |
11dbf203 | 629 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 630 | |
ee2ffa0d | 631 | spin_lock(&tty_files_lock); |
1da177e4 | 632 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
633 | list_for_each_entry(priv, &tty->tty_files, list) { |
634 | filp = priv->file; | |
1da177e4 LT |
635 | if (filp->f_op->write == redirected_tty_write) |
636 | cons_filp = filp; | |
637 | if (filp->f_op->write != tty_write) | |
638 | continue; | |
639 | closecount++; | |
ec79d605 | 640 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
641 | filp->f_op = &hung_up_tty_fops; |
642 | } | |
ee2ffa0d | 643 | spin_unlock(&tty_files_lock); |
37bdfb07 | 644 | |
25fdf243 PH |
645 | refs = tty_signal_session_leader(tty, exit_session); |
646 | /* Account for the p->signal references we killed */ | |
647 | while (refs--) | |
648 | tty_kref_put(tty); | |
649 | ||
acfa747b JS |
650 | /* |
651 | * it drops BTM and thus races with reopen | |
652 | * we protect the race by TTY_HUPPING | |
653 | */ | |
c65c9bc3 | 654 | tty_ldisc_hangup(tty); |
37bdfb07 | 655 | |
20cc225b | 656 | spin_lock_irq(&tty->ctrl_lock); |
c65c9bc3 | 657 | clear_bit(TTY_THROTTLED, &tty->flags); |
c65c9bc3 | 658 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
d9c1e9a8 EB |
659 | put_pid(tty->session); |
660 | put_pid(tty->pgrp); | |
ab521dc0 EB |
661 | tty->session = NULL; |
662 | tty->pgrp = NULL; | |
1da177e4 | 663 | tty->ctrl_status = 0; |
20cc225b | 664 | spin_unlock_irq(&tty->ctrl_lock); |
9c9f4ded | 665 | |
1da177e4 | 666 | /* |
37bdfb07 AC |
667 | * If one of the devices matches a console pointer, we |
668 | * cannot just call hangup() because that will cause | |
669 | * tty->count and state->count to go out of sync. | |
670 | * So we just call close() the right number of times. | |
1da177e4 LT |
671 | */ |
672 | if (cons_filp) { | |
f34d7a5b | 673 | if (tty->ops->close) |
1da177e4 | 674 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
675 | tty->ops->close(tty, cons_filp); |
676 | } else if (tty->ops->hangup) | |
7c6d340f | 677 | tty->ops->hangup(tty); |
37bdfb07 AC |
678 | /* |
679 | * We don't want to have driver/ldisc interactions beyond | |
680 | * the ones we did here. The driver layer expects no | |
681 | * calls after ->hangup() from the ldisc side. However we | |
682 | * can't yet guarantee all that. | |
683 | */ | |
1da177e4 | 684 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 685 | clear_bit(TTY_HUPPING, &tty->flags); |
11dbf203 | 686 | |
89c8d91e | 687 | tty_unlock(tty); |
11dbf203 | 688 | |
1da177e4 LT |
689 | if (f) |
690 | fput(f); | |
691 | } | |
692 | ||
ddcd9fb6 AB |
693 | static void do_tty_hangup(struct work_struct *work) |
694 | { | |
695 | struct tty_struct *tty = | |
696 | container_of(work, struct tty_struct, hangup_work); | |
697 | ||
f91e2590 | 698 | __tty_hangup(tty, 0); |
ddcd9fb6 AB |
699 | } |
700 | ||
af9b897e AC |
701 | /** |
702 | * tty_hangup - trigger a hangup event | |
703 | * @tty: tty to hangup | |
704 | * | |
705 | * A carrier loss (virtual or otherwise) has occurred on this like | |
706 | * schedule a hangup sequence to run after this event. | |
707 | */ | |
708 | ||
37bdfb07 | 709 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
710 | { |
711 | #ifdef TTY_DEBUG_HANGUP | |
712 | char buf[64]; | |
1da177e4 LT |
713 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
714 | #endif | |
715 | schedule_work(&tty->hangup_work); | |
716 | } | |
717 | ||
718 | EXPORT_SYMBOL(tty_hangup); | |
719 | ||
af9b897e AC |
720 | /** |
721 | * tty_vhangup - process vhangup | |
722 | * @tty: tty to hangup | |
723 | * | |
724 | * The user has asked via system call for the terminal to be hung up. | |
725 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 726 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
727 | */ |
728 | ||
37bdfb07 | 729 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
730 | { |
731 | #ifdef TTY_DEBUG_HANGUP | |
732 | char buf[64]; | |
733 | ||
734 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
735 | #endif | |
f91e2590 | 736 | __tty_hangup(tty, 0); |
1da177e4 | 737 | } |
37bdfb07 | 738 | |
1da177e4 LT |
739 | EXPORT_SYMBOL(tty_vhangup); |
740 | ||
11dbf203 | 741 | |
2cb5998b AC |
742 | /** |
743 | * tty_vhangup_self - process vhangup for own ctty | |
744 | * | |
745 | * Perform a vhangup on the current controlling tty | |
746 | */ | |
747 | ||
748 | void tty_vhangup_self(void) | |
749 | { | |
750 | struct tty_struct *tty; | |
751 | ||
2cb5998b AC |
752 | tty = get_current_tty(); |
753 | if (tty) { | |
754 | tty_vhangup(tty); | |
755 | tty_kref_put(tty); | |
756 | } | |
2cb5998b AC |
757 | } |
758 | ||
f91e2590 PH |
759 | /** |
760 | * tty_vhangup_session - hangup session leader exit | |
761 | * @tty: tty to hangup | |
762 | * | |
763 | * The session leader is exiting and hanging up its controlling terminal. | |
764 | * Every process in the foreground process group is signalled SIGHUP. | |
765 | * | |
766 | * We do this synchronously so that when the syscall returns the process | |
767 | * is complete. That guarantee is necessary for security reasons. | |
768 | */ | |
769 | ||
44a459fd | 770 | static void tty_vhangup_session(struct tty_struct *tty) |
f91e2590 PH |
771 | { |
772 | #ifdef TTY_DEBUG_HANGUP | |
773 | char buf[64]; | |
774 | ||
775 | printk(KERN_DEBUG "%s vhangup session...\n", tty_name(tty, buf)); | |
776 | #endif | |
777 | __tty_hangup(tty, 1); | |
778 | } | |
779 | ||
af9b897e AC |
780 | /** |
781 | * tty_hung_up_p - was tty hung up | |
782 | * @filp: file pointer of tty | |
783 | * | |
784 | * Return true if the tty has been subject to a vhangup or a carrier | |
785 | * loss | |
786 | */ | |
787 | ||
37bdfb07 | 788 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
789 | { |
790 | return (filp->f_op == &hung_up_tty_fops); | |
791 | } | |
792 | ||
793 | EXPORT_SYMBOL(tty_hung_up_p); | |
794 | ||
ab521dc0 | 795 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
796 | { |
797 | struct task_struct *p; | |
ab521dc0 | 798 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 799 | proc_clear_tty(p); |
ab521dc0 | 800 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
801 | } |
802 | ||
af9b897e AC |
803 | /** |
804 | * disassociate_ctty - disconnect controlling tty | |
805 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 806 | * |
af9b897e AC |
807 | * This function is typically called only by the session leader, when |
808 | * it wants to disassociate itself from its controlling tty. | |
809 | * | |
810 | * It performs the following functions: | |
1da177e4 LT |
811 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
812 | * (2) Clears the tty from being controlling the session | |
813 | * (3) Clears the controlling tty for all processes in the | |
814 | * session group. | |
815 | * | |
af9b897e AC |
816 | * The argument on_exit is set to 1 if called when a process is |
817 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
818 | * | |
24ec839c | 819 | * Locking: |
ec79d605 AB |
820 | * BTM is taken for hysterical raisins, and held when |
821 | * called from no_tty(). | |
24ec839c PZ |
822 | * tty_mutex is taken to protect tty |
823 | * ->siglock is taken to protect ->signal/->sighand | |
824 | * tasklist_lock is taken to walk process list for sessions | |
825 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 826 | */ |
af9b897e | 827 | |
1da177e4 LT |
828 | void disassociate_ctty(int on_exit) |
829 | { | |
830 | struct tty_struct *tty; | |
1da177e4 | 831 | |
5ec93d11 AC |
832 | if (!current->signal->leader) |
833 | return; | |
1da177e4 | 834 | |
24ec839c | 835 | tty = get_current_tty(); |
1da177e4 | 836 | if (tty) { |
f91e2590 PH |
837 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { |
838 | tty_vhangup_session(tty); | |
839 | } else { | |
840 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
841 | if (tty_pgrp) { | |
842 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
03e12617 ON |
843 | if (!on_exit) |
844 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
f91e2590 PH |
845 | put_pid(tty_pgrp); |
846 | } | |
1411dc4a | 847 | } |
f91e2590 PH |
848 | tty_kref_put(tty); |
849 | ||
680a9671 | 850 | } else if (on_exit) { |
ab521dc0 | 851 | struct pid *old_pgrp; |
680a9671 EB |
852 | spin_lock_irq(¤t->sighand->siglock); |
853 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 854 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 855 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 856 | if (old_pgrp) { |
ab521dc0 EB |
857 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
858 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
859 | put_pid(old_pgrp); | |
1da177e4 | 860 | } |
1da177e4 LT |
861 | return; |
862 | } | |
1da177e4 | 863 | |
24ec839c | 864 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 865 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 866 | current->signal->tty_old_pgrp = NULL; |
24ec839c | 867 | |
c70dbb1e | 868 | tty = tty_kref_get(current->signal->tty); |
24ec839c | 869 | if (tty) { |
47f86834 AC |
870 | unsigned long flags; |
871 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
872 | put_pid(tty->session); |
873 | put_pid(tty->pgrp); | |
874 | tty->session = NULL; | |
875 | tty->pgrp = NULL; | |
47f86834 | 876 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 877 | tty_kref_put(tty); |
24ec839c PZ |
878 | } else { |
879 | #ifdef TTY_DEBUG_HANGUP | |
880 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
881 | " = NULL", tty); | |
882 | #endif | |
883 | } | |
1da177e4 | 884 | |
c70dbb1e | 885 | spin_unlock_irq(¤t->sighand->siglock); |
1da177e4 LT |
886 | /* Now clear signal->tty under the lock */ |
887 | read_lock(&tasklist_lock); | |
ab521dc0 | 888 | session_clear_tty(task_session(current)); |
1da177e4 | 889 | read_unlock(&tasklist_lock); |
1da177e4 LT |
890 | } |
891 | ||
98a27ba4 EB |
892 | /** |
893 | * | |
894 | * no_tty - Ensure the current process does not have a controlling tty | |
895 | */ | |
896 | void no_tty(void) | |
897 | { | |
3af502b9 AC |
898 | /* FIXME: Review locking here. The tty_lock never covered any race |
899 | between a new association and proc_clear_tty but possible we need | |
900 | to protect against this anyway */ | |
98a27ba4 | 901 | struct task_struct *tsk = current; |
5ec93d11 | 902 | disassociate_ctty(0); |
98a27ba4 EB |
903 | proc_clear_tty(tsk); |
904 | } | |
905 | ||
af9b897e AC |
906 | |
907 | /** | |
beb7dd86 | 908 | * stop_tty - propagate flow control |
af9b897e AC |
909 | * @tty: tty to stop |
910 | * | |
01adc807 | 911 | * Perform flow control to the driver. May be called |
af9b897e AC |
912 | * on an already stopped device and will not re-call the driver |
913 | * method. | |
914 | * | |
915 | * This functionality is used by both the line disciplines for | |
916 | * halting incoming flow and by the driver. It may therefore be | |
917 | * called from any context, may be under the tty atomic_write_lock | |
918 | * but not always. | |
919 | * | |
920 | * Locking: | |
f9e053dc | 921 | * flow_lock |
af9b897e AC |
922 | */ |
923 | ||
f9e053dc | 924 | void __stop_tty(struct tty_struct *tty) |
1da177e4 | 925 | { |
f9e053dc | 926 | if (tty->stopped) |
1da177e4 LT |
927 | return; |
928 | tty->stopped = 1; | |
f34d7a5b AC |
929 | if (tty->ops->stop) |
930 | (tty->ops->stop)(tty); | |
1da177e4 LT |
931 | } |
932 | ||
f9e053dc PH |
933 | void stop_tty(struct tty_struct *tty) |
934 | { | |
935 | unsigned long flags; | |
936 | ||
937 | spin_lock_irqsave(&tty->flow_lock, flags); | |
938 | __stop_tty(tty); | |
939 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
940 | } | |
1da177e4 LT |
941 | EXPORT_SYMBOL(stop_tty); |
942 | ||
af9b897e | 943 | /** |
beb7dd86 | 944 | * start_tty - propagate flow control |
af9b897e AC |
945 | * @tty: tty to start |
946 | * | |
01adc807 PH |
947 | * Start a tty that has been stopped if at all possible. If this |
948 | * tty was previous stopped and is now being started, the driver | |
949 | * start method is invoked and the line discipline woken. | |
af9b897e AC |
950 | * |
951 | * Locking: | |
f9e053dc | 952 | * flow_lock |
af9b897e AC |
953 | */ |
954 | ||
f9e053dc | 955 | void __start_tty(struct tty_struct *tty) |
1da177e4 | 956 | { |
f9e053dc | 957 | if (!tty->stopped || tty->flow_stopped) |
1da177e4 LT |
958 | return; |
959 | tty->stopped = 0; | |
f34d7a5b AC |
960 | if (tty->ops->start) |
961 | (tty->ops->start)(tty); | |
1da177e4 | 962 | tty_wakeup(tty); |
1da177e4 LT |
963 | } |
964 | ||
f9e053dc PH |
965 | void start_tty(struct tty_struct *tty) |
966 | { | |
967 | unsigned long flags; | |
968 | ||
969 | spin_lock_irqsave(&tty->flow_lock, flags); | |
970 | __start_tty(tty); | |
971 | spin_unlock_irqrestore(&tty->flow_lock, flags); | |
972 | } | |
1da177e4 LT |
973 | EXPORT_SYMBOL(start_tty); |
974 | ||
b0b88565 | 975 | /* We limit tty time update visibility to every 8 seconds or so. */ |
37b7f3c7 JS |
976 | static void tty_update_time(struct timespec *time) |
977 | { | |
b0b88565 | 978 | unsigned long sec = get_seconds() & ~7; |
37b7f3c7 JS |
979 | if ((long)(sec - time->tv_sec) > 0) |
980 | time->tv_sec = sec; | |
981 | } | |
982 | ||
af9b897e AC |
983 | /** |
984 | * tty_read - read method for tty device files | |
985 | * @file: pointer to tty file | |
986 | * @buf: user buffer | |
987 | * @count: size of user buffer | |
988 | * @ppos: unused | |
989 | * | |
990 | * Perform the read system call function on this terminal device. Checks | |
991 | * for hung up devices before calling the line discipline method. | |
992 | * | |
993 | * Locking: | |
47f86834 AC |
994 | * Locks the line discipline internally while needed. Multiple |
995 | * read calls may be outstanding in parallel. | |
af9b897e AC |
996 | */ |
997 | ||
37bdfb07 | 998 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
999 | loff_t *ppos) |
1000 | { | |
1001 | int i; | |
37b7f3c7 | 1002 | struct inode *inode = file_inode(file); |
d996b62a | 1003 | struct tty_struct *tty = file_tty(file); |
1da177e4 LT |
1004 | struct tty_ldisc *ld; |
1005 | ||
37b7f3c7 | 1006 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1da177e4 LT |
1007 | return -EIO; |
1008 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
1009 | return -EIO; | |
1010 | ||
1011 | /* We want to wait for the line discipline to sort out in this | |
1012 | situation */ | |
1013 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
1014 | if (ld->ops->read) |
1015 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
1016 | else |
1017 | i = -EIO; | |
1018 | tty_ldisc_deref(ld); | |
b0de59b5 | 1019 | |
37b7f3c7 JS |
1020 | if (i > 0) |
1021 | tty_update_time(&inode->i_atime); | |
1022 | ||
1da177e4 LT |
1023 | return i; |
1024 | } | |
1025 | ||
9c1729db | 1026 | void tty_write_unlock(struct tty_struct *tty) |
83c67571 | 1027 | __releases(&tty->atomic_write_lock) |
9c1729db AC |
1028 | { |
1029 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 1030 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
1031 | } |
1032 | ||
1033 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
83c67571 | 1034 | __acquires(&tty->atomic_write_lock) |
9c1729db AC |
1035 | { |
1036 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
1037 | if (ndelay) | |
1038 | return -EAGAIN; | |
1039 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
1040 | return -ERESTARTSYS; | |
1041 | } | |
1042 | return 0; | |
1043 | } | |
1044 | ||
1da177e4 LT |
1045 | /* |
1046 | * Split writes up in sane blocksizes to avoid | |
1047 | * denial-of-service type attacks | |
1048 | */ | |
1049 | static inline ssize_t do_tty_write( | |
1050 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1051 | struct tty_struct *tty, | |
1052 | struct file *file, | |
1053 | const char __user *buf, | |
1054 | size_t count) | |
1055 | { | |
9c1729db | 1056 | ssize_t ret, written = 0; |
1da177e4 | 1057 | unsigned int chunk; |
37bdfb07 | 1058 | |
9c1729db AC |
1059 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1060 | if (ret < 0) | |
1061 | return ret; | |
1da177e4 LT |
1062 | |
1063 | /* | |
1064 | * We chunk up writes into a temporary buffer. This | |
1065 | * simplifies low-level drivers immensely, since they | |
1066 | * don't have locking issues and user mode accesses. | |
1067 | * | |
1068 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1069 | * big chunk-size.. | |
1070 | * | |
1071 | * The default chunk-size is 2kB, because the NTTY | |
1072 | * layer has problems with bigger chunks. It will | |
1073 | * claim to be able to handle more characters than | |
1074 | * it actually does. | |
af9b897e AC |
1075 | * |
1076 | * FIXME: This can probably go away now except that 64K chunks | |
1077 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1078 | */ |
1079 | chunk = 2048; | |
1080 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1081 | chunk = 65536; | |
1082 | if (count < chunk) | |
1083 | chunk = count; | |
1084 | ||
70522e12 | 1085 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1086 | if (tty->write_cnt < chunk) { |
402fda92 | 1087 | unsigned char *buf_chunk; |
1da177e4 LT |
1088 | |
1089 | if (chunk < 1024) | |
1090 | chunk = 1024; | |
1091 | ||
402fda92 JW |
1092 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1093 | if (!buf_chunk) { | |
9c1729db AC |
1094 | ret = -ENOMEM; |
1095 | goto out; | |
1da177e4 LT |
1096 | } |
1097 | kfree(tty->write_buf); | |
1098 | tty->write_cnt = chunk; | |
402fda92 | 1099 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1100 | } |
1101 | ||
1102 | /* Do the write .. */ | |
1103 | for (;;) { | |
1104 | size_t size = count; | |
1105 | if (size > chunk) | |
1106 | size = chunk; | |
1107 | ret = -EFAULT; | |
1108 | if (copy_from_user(tty->write_buf, buf, size)) | |
1109 | break; | |
1da177e4 | 1110 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1111 | if (ret <= 0) |
1112 | break; | |
1113 | written += ret; | |
1114 | buf += ret; | |
1115 | count -= ret; | |
1116 | if (!count) | |
1117 | break; | |
1118 | ret = -ERESTARTSYS; | |
1119 | if (signal_pending(current)) | |
1120 | break; | |
1121 | cond_resched(); | |
1122 | } | |
37b7f3c7 JS |
1123 | if (written) { |
1124 | tty_update_time(&file_inode(file)->i_mtime); | |
1da177e4 | 1125 | ret = written; |
37b7f3c7 | 1126 | } |
9c1729db AC |
1127 | out: |
1128 | tty_write_unlock(tty); | |
1da177e4 LT |
1129 | return ret; |
1130 | } | |
1131 | ||
95f9bfc6 AC |
1132 | /** |
1133 | * tty_write_message - write a message to a certain tty, not just the console. | |
1134 | * @tty: the destination tty_struct | |
1135 | * @msg: the message to write | |
1136 | * | |
1137 | * This is used for messages that need to be redirected to a specific tty. | |
1138 | * We don't put it into the syslog queue right now maybe in the future if | |
1139 | * really needed. | |
1140 | * | |
ec79d605 | 1141 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1142 | */ |
1143 | ||
1144 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1145 | { | |
95f9bfc6 AC |
1146 | if (tty) { |
1147 | mutex_lock(&tty->atomic_write_lock); | |
89c8d91e | 1148 | tty_lock(tty); |
eeb89d91 | 1149 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
89c8d91e | 1150 | tty_unlock(tty); |
95f9bfc6 | 1151 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1152 | } else |
89c8d91e | 1153 | tty_unlock(tty); |
95f9bfc6 AC |
1154 | tty_write_unlock(tty); |
1155 | } | |
95f9bfc6 AC |
1156 | return; |
1157 | } | |
1158 | ||
1da177e4 | 1159 | |
af9b897e AC |
1160 | /** |
1161 | * tty_write - write method for tty device file | |
1162 | * @file: tty file pointer | |
1163 | * @buf: user data to write | |
1164 | * @count: bytes to write | |
1165 | * @ppos: unused | |
1166 | * | |
1167 | * Write data to a tty device via the line discipline. | |
1168 | * | |
1169 | * Locking: | |
1170 | * Locks the line discipline as required | |
1171 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1172 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1173 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1174 | */ |
1175 | ||
37bdfb07 AC |
1176 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1177 | size_t count, loff_t *ppos) | |
1da177e4 | 1178 | { |
d996b62a NP |
1179 | struct tty_struct *tty = file_tty(file); |
1180 | struct tty_ldisc *ld; | |
1da177e4 | 1181 | ssize_t ret; |
37bdfb07 | 1182 | |
6131ffaa | 1183 | if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
1da177e4 | 1184 | return -EIO; |
f34d7a5b | 1185 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1186 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1187 | return -EIO; | |
f34d7a5b AC |
1188 | /* Short term debug to catch buggy drivers */ |
1189 | if (tty->ops->write_room == NULL) | |
1190 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1191 | tty->driver->name); | |
37bdfb07 | 1192 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1193 | if (!ld->ops->write) |
1da177e4 LT |
1194 | ret = -EIO; |
1195 | else | |
a352def2 | 1196 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1197 | tty_ldisc_deref(ld); |
1198 | return ret; | |
1199 | } | |
1200 | ||
37bdfb07 AC |
1201 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1202 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1203 | { |
1204 | struct file *p = NULL; | |
1205 | ||
1206 | spin_lock(&redirect_lock); | |
cb0942b8 AV |
1207 | if (redirect) |
1208 | p = get_file(redirect); | |
1da177e4 LT |
1209 | spin_unlock(&redirect_lock); |
1210 | ||
1211 | if (p) { | |
1212 | ssize_t res; | |
1213 | res = vfs_write(p, buf, count, &p->f_pos); | |
1214 | fput(p); | |
1215 | return res; | |
1216 | } | |
1da177e4 LT |
1217 | return tty_write(file, buf, count, ppos); |
1218 | } | |
1219 | ||
1220 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1221 | ||
af9b897e AC |
1222 | /** |
1223 | * pty_line_name - generate name for a pty | |
1224 | * @driver: the tty driver in use | |
1225 | * @index: the minor number | |
1226 | * @p: output buffer of at least 6 bytes | |
1227 | * | |
1228 | * Generate a name from a driver reference and write it to the output | |
1229 | * buffer. | |
1230 | * | |
1231 | * Locking: None | |
1232 | */ | |
1233 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1234 | { |
1235 | int i = index + driver->name_base; | |
1236 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1237 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1238 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1239 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1240 | } |
1241 | ||
af9b897e | 1242 | /** |
8b0a88d5 | 1243 | * tty_line_name - generate name for a tty |
af9b897e AC |
1244 | * @driver: the tty driver in use |
1245 | * @index: the minor number | |
1246 | * @p: output buffer of at least 7 bytes | |
1247 | * | |
1248 | * Generate a name from a driver reference and write it to the output | |
5c0a2450 | 1249 | * buffer. |
af9b897e AC |
1250 | * |
1251 | * Locking: None | |
1252 | */ | |
723abd87 | 1253 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
1da177e4 | 1254 | { |
0019b408 | 1255 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
723abd87 | 1256 | return sprintf(p, "%s", driver->name); |
0019b408 | 1257 | else |
723abd87 HR |
1258 | return sprintf(p, "%s%d", driver->name, |
1259 | index + driver->name_base); | |
1da177e4 LT |
1260 | } |
1261 | ||
99f1fe18 AC |
1262 | /** |
1263 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1264 | * @driver: the driver for the tty | |
1265 | * @idx: the minor number | |
23499705 | 1266 | * |
99f1fe18 | 1267 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1268 | * |
99f1fe18 AC |
1269 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1270 | * be held until the 'fast-open' is also done. Will change once we | |
1271 | * have refcounting in the driver and per driver locking | |
23499705 | 1272 | */ |
a47d545f | 1273 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1274 | struct inode *inode, int idx) |
23499705 | 1275 | { |
99f1fe18 | 1276 | if (driver->ops->lookup) |
15f1a633 | 1277 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1278 | |
d4834267 | 1279 | return driver->ttys[idx]; |
23499705 SB |
1280 | } |
1281 | ||
bf970ee4 AC |
1282 | /** |
1283 | * tty_init_termios - helper for termios setup | |
1284 | * @tty: the tty to set up | |
1285 | * | |
1286 | * Initialise the termios structures for this tty. Thus runs under | |
1287 | * the tty_mutex currently so we can be relaxed about ordering. | |
1288 | */ | |
1289 | ||
1290 | int tty_init_termios(struct tty_struct *tty) | |
1291 | { | |
fe6e29fd | 1292 | struct ktermios *tp; |
bf970ee4 AC |
1293 | int idx = tty->index; |
1294 | ||
36b3c070 AC |
1295 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
1296 | tty->termios = tty->driver->init_termios; | |
1297 | else { | |
1298 | /* Check for lazy saved data */ | |
1299 | tp = tty->driver->termios[idx]; | |
1300 | if (tp != NULL) | |
1301 | tty->termios = *tp; | |
1302 | else | |
1303 | tty->termios = tty->driver->init_termios; | |
bf970ee4 | 1304 | } |
bf970ee4 | 1305 | /* Compatibility until drivers always set this */ |
adc8d746 AC |
1306 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
1307 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); | |
bf970ee4 AC |
1308 | return 0; |
1309 | } | |
fe1ae7fd | 1310 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1311 | |
66d450e8 JS |
1312 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1313 | { | |
1314 | int ret = tty_init_termios(tty); | |
1315 | if (ret) | |
1316 | return ret; | |
1317 | ||
1318 | tty_driver_kref_get(driver); | |
1319 | tty->count++; | |
1320 | driver->ttys[tty->index] = tty; | |
1321 | return 0; | |
1322 | } | |
1323 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1324 | ||
99f1fe18 | 1325 | /** |
8b0a88d5 AC |
1326 | * tty_driver_install_tty() - install a tty entry in the driver |
1327 | * @driver: the driver for the tty | |
1328 | * @tty: the tty | |
1329 | * | |
1330 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1331 | * will be set by the time this is called. This method is responsible |
1332 | * for ensuring any need additional structures are allocated and | |
1333 | * configured. | |
8b0a88d5 AC |
1334 | * |
1335 | * Locking: tty_mutex for now | |
1336 | */ | |
1337 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1338 | struct tty_struct *tty) | |
1339 | { | |
66d450e8 JS |
1340 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1341 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1342 | } |
1343 | ||
1344 | /** | |
1345 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1346 | * @driver: the driver for the tty | |
1347 | * @idx: the minor number | |
1348 | * | |
1349 | * Remvoe a tty object from the driver tables. The tty->index field | |
1350 | * will be set by the time this is called. | |
1351 | * | |
1352 | * Locking: tty_mutex for now | |
1353 | */ | |
24d406a6 | 1354 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1355 | { |
1356 | if (driver->ops->remove) | |
1357 | driver->ops->remove(driver, tty); | |
1358 | else | |
1359 | driver->ttys[tty->index] = NULL; | |
1360 | } | |
1361 | ||
1362 | /* | |
1363 | * tty_reopen() - fast re-open of an open tty | |
1364 | * @tty - the tty to open | |
23499705 | 1365 | * |
99f1fe18 | 1366 | * Return 0 on success, -errno on error. |
23499705 | 1367 | * |
99f1fe18 AC |
1368 | * Locking: tty_mutex must be held from the time the tty was found |
1369 | * till this open completes. | |
23499705 | 1370 | */ |
99f1fe18 | 1371 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1372 | { |
1373 | struct tty_driver *driver = tty->driver; | |
1374 | ||
e2efafbf | 1375 | if (test_bit(TTY_CLOSING, &tty->flags) || |
36697529 | 1376 | test_bit(TTY_HUPPING, &tty->flags)) |
23499705 SB |
1377 | return -EIO; |
1378 | ||
1379 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1380 | driver->subtype == PTY_TYPE_MASTER) { | |
1381 | /* | |
1382 | * special case for PTY masters: only one open permitted, | |
1383 | * and the slave side open count is incremented as well. | |
1384 | */ | |
1385 | if (tty->count) | |
1386 | return -EIO; | |
1387 | ||
1388 | tty->link->count++; | |
1389 | } | |
1390 | tty->count++; | |
23499705 | 1391 | |
36697529 | 1392 | WARN_ON(!tty->ldisc); |
23499705 SB |
1393 | |
1394 | return 0; | |
1395 | } | |
1396 | ||
af9b897e | 1397 | /** |
d81ed103 | 1398 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1399 | * @driver: tty driver we are opening a device on |
1400 | * @idx: device index | |
15582d36 | 1401 | * @ret_tty: returned tty structure |
af9b897e AC |
1402 | * |
1403 | * Prepare a tty device. This may not be a "new" clean device but | |
1404 | * could also be an active device. The pty drivers require special | |
1405 | * handling because of this. | |
1406 | * | |
1407 | * Locking: | |
1408 | * The function is called under the tty_mutex, which | |
1409 | * protects us from the tty struct or driver itself going away. | |
1410 | * | |
1411 | * On exit the tty device has the line discipline attached and | |
1412 | * a reference count of 1. If a pair was created for pty/tty use | |
1413 | * and the other was a pty master then it too has a reference count of 1. | |
1414 | * | |
1da177e4 | 1415 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1416 | * failed open. The new code protects the open with a mutex, so it's |
1417 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1418 | * relaxed for the (most common) case of reopening a tty. |
1419 | */ | |
af9b897e | 1420 | |
593a27c4 | 1421 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1422 | { |
bf970ee4 | 1423 | struct tty_struct *tty; |
73ec06fc | 1424 | int retval; |
1da177e4 | 1425 | |
1da177e4 LT |
1426 | /* |
1427 | * First time open is complex, especially for PTY devices. | |
1428 | * This code guarantees that either everything succeeds and the | |
1429 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1430 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1431 | * and locked termios may be retained.) |
1432 | */ | |
1433 | ||
73ec06fc AC |
1434 | if (!try_module_get(driver->owner)) |
1435 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1436 | |
2c964a2f | 1437 | tty = alloc_tty_struct(driver, idx); |
d5543503 JS |
1438 | if (!tty) { |
1439 | retval = -ENOMEM; | |
1440 | goto err_module_put; | |
1441 | } | |
1da177e4 | 1442 | |
89c8d91e | 1443 | tty_lock(tty); |
73ec06fc | 1444 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1445 | if (retval < 0) |
a9dccddb | 1446 | goto err_deinit_tty; |
8b0a88d5 | 1447 | |
04831dc1 JS |
1448 | if (!tty->port) |
1449 | tty->port = driver->ports[idx]; | |
1450 | ||
5d4121c0 JS |
1451 | WARN_RATELIMIT(!tty->port, |
1452 | "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", | |
1453 | __func__, tty->driver->name); | |
1454 | ||
967fab69 JS |
1455 | tty->port->itty = tty; |
1456 | ||
37bdfb07 | 1457 | /* |
1da177e4 | 1458 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1459 | * If we fail here just call release_tty to clean up. No need |
1460 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1461 | */ |
bf970ee4 | 1462 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1463 | if (retval) |
d5543503 | 1464 | goto err_release_tty; |
89c8d91e | 1465 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1466 | return tty; |
1da177e4 | 1467 | |
a9dccddb | 1468 | err_deinit_tty: |
89c8d91e | 1469 | tty_unlock(tty); |
a9dccddb | 1470 | deinitialize_tty_struct(tty); |
d5543503 JS |
1471 | free_tty_struct(tty); |
1472 | err_module_put: | |
1da177e4 | 1473 | module_put(driver->owner); |
d5543503 | 1474 | return ERR_PTR(retval); |
1da177e4 | 1475 | |
d5698c28 | 1476 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1477 | err_release_tty: |
89c8d91e | 1478 | tty_unlock(tty); |
5a3c6b25 | 1479 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1480 | "clearing slot %d\n", idx); |
d5698c28 | 1481 | release_tty(tty, idx); |
73ec06fc | 1482 | return ERR_PTR(retval); |
1da177e4 LT |
1483 | } |
1484 | ||
feebed65 AC |
1485 | void tty_free_termios(struct tty_struct *tty) |
1486 | { | |
1487 | struct ktermios *tp; | |
1488 | int idx = tty->index; | |
36b3c070 AC |
1489 | |
1490 | /* If the port is going to reset then it has no termios to save */ | |
1491 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) | |
1492 | return; | |
1493 | ||
1494 | /* Stash the termios data */ | |
1495 | tp = tty->driver->termios[idx]; | |
1496 | if (tp == NULL) { | |
1497 | tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
1498 | if (tp == NULL) { | |
1499 | pr_warn("tty: no memory to save termios state.\n"); | |
1500 | return; | |
1501 | } | |
4ac5d705 | 1502 | tty->driver->termios[idx] = tp; |
feebed65 | 1503 | } |
36b3c070 | 1504 | *tp = tty->termios; |
feebed65 AC |
1505 | } |
1506 | EXPORT_SYMBOL(tty_free_termios); | |
1507 | ||
a2965b7b PH |
1508 | /** |
1509 | * tty_flush_works - flush all works of a tty | |
1510 | * @tty: tty device to flush works for | |
1511 | * | |
1512 | * Sync flush all works belonging to @tty. | |
1513 | */ | |
1514 | static void tty_flush_works(struct tty_struct *tty) | |
1515 | { | |
1516 | flush_work(&tty->SAK_work); | |
1517 | flush_work(&tty->hangup_work); | |
1518 | } | |
feebed65 | 1519 | |
af9b897e | 1520 | /** |
d5698c28 | 1521 | * release_one_tty - release tty structure memory |
9c9f4ded | 1522 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1523 | * |
1524 | * Releases memory associated with a tty structure, and clears out the | |
1525 | * driver table slots. This function is called when a device is no longer | |
1526 | * in use. It also gets called when setup of a device fails. | |
1527 | * | |
1528 | * Locking: | |
af9b897e AC |
1529 | * takes the file list lock internally when working on the list |
1530 | * of ttys that the driver keeps. | |
b50989dc AC |
1531 | * |
1532 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1533 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1534 | */ |
b50989dc | 1535 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1536 | { |
b50989dc AC |
1537 | struct tty_struct *tty = |
1538 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1539 | struct tty_driver *driver = tty->driver; |
b216df53 | 1540 | struct module *owner = driver->owner; |
d5698c28 | 1541 | |
f278a2f7 DY |
1542 | if (tty->ops->cleanup) |
1543 | tty->ops->cleanup(tty); | |
1544 | ||
1da177e4 | 1545 | tty->magic = 0; |
7d7b93c1 | 1546 | tty_driver_kref_put(driver); |
b216df53 | 1547 | module_put(owner); |
d5698c28 | 1548 | |
ee2ffa0d | 1549 | spin_lock(&tty_files_lock); |
1da177e4 | 1550 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1551 | spin_unlock(&tty_files_lock); |
d5698c28 | 1552 | |
6da8d866 ON |
1553 | put_pid(tty->pgrp); |
1554 | put_pid(tty->session); | |
1da177e4 LT |
1555 | free_tty_struct(tty); |
1556 | } | |
1557 | ||
b50989dc AC |
1558 | static void queue_release_one_tty(struct kref *kref) |
1559 | { | |
1560 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 | 1561 | |
b50989dc AC |
1562 | /* The hangup queue is now free so we can reuse it rather than |
1563 | waste a chunk of memory for each port */ | |
1564 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1565 | schedule_work(&tty->hangup_work); | |
1566 | } | |
1567 | ||
9c9f4ded AC |
1568 | /** |
1569 | * tty_kref_put - release a tty kref | |
1570 | * @tty: tty device | |
1571 | * | |
1572 | * Release a reference to a tty device and if need be let the kref | |
1573 | * layer destruct the object for us | |
1574 | */ | |
1575 | ||
1576 | void tty_kref_put(struct tty_struct *tty) | |
1577 | { | |
1578 | if (tty) | |
b50989dc | 1579 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1580 | } |
1581 | EXPORT_SYMBOL(tty_kref_put); | |
1582 | ||
d5698c28 CH |
1583 | /** |
1584 | * release_tty - release tty structure memory | |
1585 | * | |
1586 | * Release both @tty and a possible linked partner (think pty pair), | |
1587 | * and decrement the refcount of the backing module. | |
1588 | * | |
1589 | * Locking: | |
d155255a | 1590 | * tty_mutex |
d5698c28 CH |
1591 | * takes the file list lock internally when working on the list |
1592 | * of ttys that the driver keeps. | |
9c9f4ded | 1593 | * |
d5698c28 CH |
1594 | */ |
1595 | static void release_tty(struct tty_struct *tty, int idx) | |
1596 | { | |
9c9f4ded AC |
1597 | /* This should always be true but check for the moment */ |
1598 | WARN_ON(tty->index != idx); | |
d155255a | 1599 | WARN_ON(!mutex_is_locked(&tty_mutex)); |
36b3c070 AC |
1600 | if (tty->ops->shutdown) |
1601 | tty->ops->shutdown(tty); | |
1602 | tty_free_termios(tty); | |
1603 | tty_driver_remove_tty(tty->driver, tty); | |
967fab69 | 1604 | tty->port->itty = NULL; |
64e377dc PH |
1605 | if (tty->link) |
1606 | tty->link->port->itty = NULL; | |
4f98d467 | 1607 | cancel_work_sync(&tty->port->buf.work); |
36b3c070 | 1608 | |
d5698c28 | 1609 | if (tty->link) |
9c9f4ded AC |
1610 | tty_kref_put(tty->link); |
1611 | tty_kref_put(tty); | |
d5698c28 CH |
1612 | } |
1613 | ||
955787ca JS |
1614 | /** |
1615 | * tty_release_checks - check a tty before real release | |
1616 | * @tty: tty to check | |
1617 | * @o_tty: link of @tty (if any) | |
1618 | * @idx: index of the tty | |
1619 | * | |
1620 | * Performs some paranoid checking before true release of the @tty. | |
1621 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1622 | */ | |
1623 | static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty, | |
1624 | int idx) | |
1625 | { | |
1626 | #ifdef TTY_PARANOIA_CHECK | |
1627 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1628 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1629 | __func__, tty->name); | |
955787ca JS |
1630 | return -1; |
1631 | } | |
1632 | ||
1633 | /* not much to check for devpts */ | |
1634 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1635 | return 0; | |
1636 | ||
1637 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1638 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1639 | __func__, idx, tty->name); | |
955787ca JS |
1640 | return -1; |
1641 | } | |
955787ca JS |
1642 | if (tty->driver->other) { |
1643 | if (o_tty != tty->driver->other->ttys[idx]) { | |
9de44bd6 JS |
1644 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1645 | __func__, idx, tty->name); | |
955787ca JS |
1646 | return -1; |
1647 | } | |
955787ca | 1648 | if (o_tty->link != tty) { |
9de44bd6 | 1649 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1650 | return -1; |
1651 | } | |
1652 | } | |
1653 | #endif | |
1654 | return 0; | |
1655 | } | |
1656 | ||
eeb89d91 AC |
1657 | /** |
1658 | * tty_release - vfs callback for close | |
1659 | * @inode: inode of tty | |
1660 | * @filp: file pointer for handle to tty | |
1661 | * | |
1662 | * Called the last time each file handle is closed that references | |
1663 | * this tty. There may however be several such references. | |
1664 | * | |
1665 | * Locking: | |
1666 | * Takes bkl. See tty_release_dev | |
1667 | * | |
1da177e4 LT |
1668 | * Even releasing the tty structures is a tricky business.. We have |
1669 | * to be very careful that the structures are all released at the | |
1670 | * same time, as interrupts might otherwise get the wrong pointers. | |
1671 | * | |
1672 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1673 | * lead to double frees or releasing memory still in use. | |
1674 | */ | |
eeb89d91 AC |
1675 | |
1676 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1677 | { |
d996b62a NP |
1678 | struct tty_struct *tty = file_tty(filp); |
1679 | struct tty_struct *o_tty; | |
1da177e4 | 1680 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
1da177e4 LT |
1681 | int idx; |
1682 | char buf[64]; | |
37bdfb07 | 1683 | |
9de44bd6 | 1684 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1685 | return 0; |
1da177e4 | 1686 | |
89c8d91e | 1687 | tty_lock(tty); |
9de44bd6 | 1688 | check_tty_count(tty, __func__); |
1da177e4 | 1689 | |
ec79d605 | 1690 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1691 | |
1692 | idx = tty->index; | |
1693 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1694 | tty->driver->subtype == PTY_TYPE_MASTER); | |
89c8d91e | 1695 | /* Review: parallel close */ |
1da177e4 LT |
1696 | o_tty = tty->link; |
1697 | ||
955787ca | 1698 | if (tty_release_checks(tty, o_tty, idx)) { |
89c8d91e | 1699 | tty_unlock(tty); |
eeb89d91 | 1700 | return 0; |
1da177e4 | 1701 | } |
1da177e4 LT |
1702 | |
1703 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1704 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1705 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1706 | #endif |
1707 | ||
f34d7a5b AC |
1708 | if (tty->ops->close) |
1709 | tty->ops->close(tty, filp); | |
1da177e4 | 1710 | |
89c8d91e | 1711 | tty_unlock(tty); |
1da177e4 LT |
1712 | /* |
1713 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1714 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1715 | * wait queues and kick everyone out _before_ actually starting to | |
1716 | * close. This ensures that we won't block while releasing the tty | |
1717 | * structure. | |
1718 | * | |
1719 | * The test for the o_tty closing is necessary, since the master and | |
1720 | * slave sides may close in any order. If the slave side closes out | |
1721 | * first, its count will be one, since the master side holds an open. | |
1722 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1723 | * so we do it now. | |
1724 | * | |
1725 | * Note that it's possible for the tty to be opened again while we're | |
1726 | * flushing out waiters. By recalculating the closing flags before | |
1727 | * each iteration we avoid any problems. | |
1728 | */ | |
1729 | while (1) { | |
1730 | /* Guard against races with tty->count changes elsewhere and | |
1731 | opens on /dev/tty */ | |
37bdfb07 | 1732 | |
70522e12 | 1733 | mutex_lock(&tty_mutex); |
89c8d91e | 1734 | tty_lock_pair(tty, o_tty); |
1da177e4 LT |
1735 | tty_closing = tty->count <= 1; |
1736 | o_tty_closing = o_tty && | |
1737 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1738 | do_sleep = 0; |
1739 | ||
1740 | if (tty_closing) { | |
1741 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1742 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1743 | do_sleep++; |
1744 | } | |
1745 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1746 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1747 | do_sleep++; |
1748 | } | |
1749 | } | |
1750 | if (o_tty_closing) { | |
1751 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1752 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1753 | do_sleep++; |
1754 | } | |
1755 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1756 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1757 | do_sleep++; |
1758 | } | |
1759 | } | |
1760 | if (!do_sleep) | |
1761 | break; | |
1762 | ||
9de44bd6 JS |
1763 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", |
1764 | __func__, tty_name(tty, buf)); | |
89c8d91e | 1765 | tty_unlock_pair(tty, o_tty); |
70522e12 | 1766 | mutex_unlock(&tty_mutex); |
1da177e4 | 1767 | schedule(); |
37bdfb07 | 1768 | } |
1da177e4 LT |
1769 | |
1770 | /* | |
37bdfb07 AC |
1771 | * The closing flags are now consistent with the open counts on |
1772 | * both sides, and we've completed the last operation that could | |
1da177e4 | 1773 | * block, so it's safe to proceed with closing. |
d155255a AC |
1774 | * |
1775 | * We must *not* drop the tty_mutex until we ensure that a further | |
1776 | * entry into tty_open can not pick up this tty. | |
1da177e4 | 1777 | */ |
1da177e4 LT |
1778 | if (pty_master) { |
1779 | if (--o_tty->count < 0) { | |
9de44bd6 JS |
1780 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1781 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1782 | o_tty->count = 0; |
1783 | } | |
1784 | } | |
1785 | if (--tty->count < 0) { | |
9de44bd6 JS |
1786 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1787 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1788 | tty->count = 0; |
1789 | } | |
37bdfb07 | 1790 | |
1da177e4 LT |
1791 | /* |
1792 | * We've decremented tty->count, so we need to remove this file | |
1793 | * descriptor off the tty->tty_files list; this serves two | |
1794 | * purposes: | |
1795 | * - check_tty_count sees the correct number of file descriptors | |
1796 | * associated with this tty. | |
1797 | * - do_tty_hangup no longer sees this file descriptor as | |
1798 | * something that needs to be handled for hangups. | |
1799 | */ | |
d996b62a | 1800 | tty_del_file(filp); |
1da177e4 LT |
1801 | |
1802 | /* | |
1803 | * Perform some housekeeping before deciding whether to return. | |
1804 | * | |
1805 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1806 | * case of a pty we may have to wait around for the other side | |
1807 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1808 | */ | |
37bdfb07 | 1809 | if (tty_closing) |
1da177e4 | 1810 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1811 | if (o_tty_closing) |
1da177e4 LT |
1812 | set_bit(TTY_CLOSING, &o_tty->flags); |
1813 | ||
1814 | /* | |
1815 | * If _either_ side is closing, make sure there aren't any | |
1816 | * processes that still think tty or o_tty is their controlling | |
1817 | * tty. | |
1818 | */ | |
1819 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1820 | read_lock(&tasklist_lock); |
24ec839c | 1821 | session_clear_tty(tty->session); |
1da177e4 | 1822 | if (o_tty) |
24ec839c | 1823 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1824 | read_unlock(&tasklist_lock); |
1825 | } | |
1826 | ||
70522e12 | 1827 | mutex_unlock(&tty_mutex); |
89c8d91e | 1828 | tty_unlock_pair(tty, o_tty); |
d155255a AC |
1829 | /* At this point the TTY_CLOSING flag should ensure a dead tty |
1830 | cannot be re-opened by a racing opener */ | |
da965822 | 1831 | |
1da177e4 | 1832 | /* check whether both sides are closing ... */ |
d155255a | 1833 | if (!tty_closing || (o_tty && !o_tty_closing)) |
eeb89d91 | 1834 | return 0; |
37bdfb07 | 1835 | |
1da177e4 | 1836 | #ifdef TTY_DEBUG_HANGUP |
96433d10 | 1837 | printk(KERN_DEBUG "%s: %s: final close\n", __func__, tty_name(tty, buf)); |
1da177e4 LT |
1838 | #endif |
1839 | /* | |
01e1abb2 | 1840 | * Ask the line discipline code to release its structures |
1da177e4 | 1841 | */ |
01e1abb2 | 1842 | tty_ldisc_release(tty, o_tty); |
a2965b7b PH |
1843 | |
1844 | /* Wait for pending work before tty destruction commmences */ | |
1845 | tty_flush_works(tty); | |
1846 | if (o_tty) | |
1847 | tty_flush_works(o_tty); | |
1848 | ||
96433d10 PH |
1849 | #ifdef TTY_DEBUG_HANGUP |
1850 | printk(KERN_DEBUG "%s: %s: freeing structure...\n", __func__, tty_name(tty, buf)); | |
1851 | #endif | |
1da177e4 | 1852 | /* |
d5698c28 | 1853 | * The release_tty function takes care of the details of clearing |
89c8d91e AC |
1854 | * the slots and preserving the termios structure. The tty_unlock_pair |
1855 | * should be safe as we keep a kref while the tty is locked (so the | |
1856 | * unlock never unlocks a freed tty). | |
1da177e4 | 1857 | */ |
d155255a | 1858 | mutex_lock(&tty_mutex); |
d5698c28 | 1859 | release_tty(tty, idx); |
d155255a | 1860 | mutex_unlock(&tty_mutex); |
1da177e4 | 1861 | |
eeb89d91 | 1862 | return 0; |
1da177e4 LT |
1863 | } |
1864 | ||
b82154ac JS |
1865 | /** |
1866 | * tty_open_current_tty - get tty of current task for open | |
1867 | * @device: device number | |
1868 | * @filp: file pointer to tty | |
1869 | * @return: tty of the current task iff @device is /dev/tty | |
1870 | * | |
1871 | * We cannot return driver and index like for the other nodes because | |
1872 | * devpts will not work then. It expects inodes to be from devpts FS. | |
3af502b9 AC |
1873 | * |
1874 | * We need to move to returning a refcounted object from all the lookup | |
1875 | * paths including this one. | |
b82154ac JS |
1876 | */ |
1877 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1878 | { | |
1879 | struct tty_struct *tty; | |
1880 | ||
1881 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1882 | return NULL; | |
1883 | ||
1884 | tty = get_current_tty(); | |
1885 | if (!tty) | |
1886 | return ERR_PTR(-ENXIO); | |
1887 | ||
1888 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1889 | /* noctty = 1; */ | |
1890 | tty_kref_put(tty); | |
1891 | /* FIXME: we put a reference and return a TTY! */ | |
3af502b9 | 1892 | /* This is only safe because the caller holds tty_mutex */ |
b82154ac JS |
1893 | return tty; |
1894 | } | |
1895 | ||
5b5e7040 JS |
1896 | /** |
1897 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1898 | * @device: device number | |
1899 | * @filp: file pointer to tty | |
1900 | * @noctty: set if the device should not become a controlling tty | |
1901 | * @index: index for the device in the @return driver | |
1902 | * @return: driver for this inode (with increased refcount) | |
1903 | * | |
1904 | * If @return is not erroneous, the caller is responsible to decrement the | |
1905 | * refcount by tty_driver_kref_put. | |
1906 | * | |
1907 | * Locking: tty_mutex protects get_tty_driver | |
1908 | */ | |
1909 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1910 | int *noctty, int *index) | |
1911 | { | |
1912 | struct tty_driver *driver; | |
1913 | ||
2cd0050c | 1914 | switch (device) { |
5b5e7040 | 1915 | #ifdef CONFIG_VT |
2cd0050c | 1916 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1917 | extern struct tty_driver *console_driver; |
1918 | driver = tty_driver_kref_get(console_driver); | |
1919 | *index = fg_console; | |
1920 | *noctty = 1; | |
2cd0050c | 1921 | break; |
5b5e7040 JS |
1922 | } |
1923 | #endif | |
2cd0050c | 1924 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1925 | struct tty_driver *console_driver = console_device(index); |
1926 | if (console_driver) { | |
1927 | driver = tty_driver_kref_get(console_driver); | |
1928 | if (driver) { | |
1929 | /* Don't let /dev/console block */ | |
1930 | filp->f_flags |= O_NONBLOCK; | |
1931 | *noctty = 1; | |
2cd0050c | 1932 | break; |
5b5e7040 JS |
1933 | } |
1934 | } | |
1935 | return ERR_PTR(-ENODEV); | |
1936 | } | |
2cd0050c JS |
1937 | default: |
1938 | driver = get_tty_driver(device, index); | |
1939 | if (!driver) | |
1940 | return ERR_PTR(-ENODEV); | |
1941 | break; | |
1942 | } | |
5b5e7040 JS |
1943 | return driver; |
1944 | } | |
1945 | ||
af9b897e | 1946 | /** |
eeb89d91 | 1947 | * tty_open - open a tty device |
af9b897e AC |
1948 | * @inode: inode of device file |
1949 | * @filp: file pointer to tty | |
1da177e4 | 1950 | * |
af9b897e AC |
1951 | * tty_open and tty_release keep up the tty count that contains the |
1952 | * number of opens done on a tty. We cannot use the inode-count, as | |
1953 | * different inodes might point to the same tty. | |
1da177e4 | 1954 | * |
af9b897e AC |
1955 | * Open-counting is needed for pty masters, as well as for keeping |
1956 | * track of serial lines: DTR is dropped when the last close happens. | |
1957 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1958 | * | |
1959 | * The termios state of a pty is reset on first open so that | |
1960 | * settings don't persist across reuse. | |
1961 | * | |
5b5e7040 | 1962 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1963 | * tty->count should protect the rest. |
1964 | * ->siglock protects ->signal/->sighand | |
89c8d91e AC |
1965 | * |
1966 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
1967 | * tty_mutex | |
1da177e4 | 1968 | */ |
af9b897e | 1969 | |
eeb89d91 | 1970 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1971 | { |
b82154ac | 1972 | struct tty_struct *tty; |
1da177e4 | 1973 | int noctty, retval; |
b82154ac | 1974 | struct tty_driver *driver = NULL; |
1da177e4 LT |
1975 | int index; |
1976 | dev_t device = inode->i_rdev; | |
846c151a | 1977 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1978 | |
1979 | nonseekable_open(inode, filp); | |
37bdfb07 | 1980 | |
1da177e4 | 1981 | retry_open: |
fa90e1c9 JS |
1982 | retval = tty_alloc_file(filp); |
1983 | if (retval) | |
1984 | return -ENOMEM; | |
1985 | ||
1da177e4 LT |
1986 | noctty = filp->f_flags & O_NOCTTY; |
1987 | index = -1; | |
1988 | retval = 0; | |
37bdfb07 | 1989 | |
70522e12 | 1990 | mutex_lock(&tty_mutex); |
89c8d91e | 1991 | /* This is protected by the tty_mutex */ |
b82154ac JS |
1992 | tty = tty_open_current_tty(device, filp); |
1993 | if (IS_ERR(tty)) { | |
ba5db448 JS |
1994 | retval = PTR_ERR(tty); |
1995 | goto err_unlock; | |
5b5e7040 JS |
1996 | } else if (!tty) { |
1997 | driver = tty_lookup_driver(device, filp, &noctty, &index); | |
1998 | if (IS_ERR(driver)) { | |
ba5db448 JS |
1999 | retval = PTR_ERR(driver); |
2000 | goto err_unlock; | |
1da177e4 | 2001 | } |
1da177e4 | 2002 | |
4a2b5fdd | 2003 | /* check whether we're reopening an existing tty */ |
15f1a633 | 2004 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 2005 | if (IS_ERR(tty)) { |
ba5db448 JS |
2006 | retval = PTR_ERR(tty); |
2007 | goto err_unlock; | |
808ffa3d | 2008 | } |
4a2b5fdd SB |
2009 | } |
2010 | ||
2011 | if (tty) { | |
89c8d91e | 2012 | tty_lock(tty); |
4a2b5fdd | 2013 | retval = tty_reopen(tty); |
89c8d91e AC |
2014 | if (retval < 0) { |
2015 | tty_unlock(tty); | |
4a2b5fdd | 2016 | tty = ERR_PTR(retval); |
89c8d91e AC |
2017 | } |
2018 | } else /* Returns with the tty_lock held for now */ | |
593a27c4 | 2019 | tty = tty_init_dev(driver, index); |
4a2b5fdd | 2020 | |
70522e12 | 2021 | mutex_unlock(&tty_mutex); |
b82154ac JS |
2022 | if (driver) |
2023 | tty_driver_kref_put(driver); | |
eeb89d91 | 2024 | if (IS_ERR(tty)) { |
ba5db448 JS |
2025 | retval = PTR_ERR(tty); |
2026 | goto err_file; | |
eeb89d91 | 2027 | } |
1da177e4 | 2028 | |
fa90e1c9 | 2029 | tty_add_file(tty, filp); |
d996b62a | 2030 | |
9de44bd6 | 2031 | check_tty_count(tty, __func__); |
1da177e4 LT |
2032 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
2033 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2034 | noctty = 1; | |
2035 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 2036 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 2037 | #endif |
909bc774 HRK |
2038 | if (tty->ops->open) |
2039 | retval = tty->ops->open(tty, filp); | |
2040 | else | |
2041 | retval = -ENODEV; | |
1da177e4 LT |
2042 | filp->f_flags = saved_flags; |
2043 | ||
37bdfb07 AC |
2044 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
2045 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
2046 | retval = -EBUSY; |
2047 | ||
2048 | if (retval) { | |
2049 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
2050 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
2051 | retval, tty->name); | |
1da177e4 | 2052 | #endif |
89c8d91e | 2053 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 2054 | tty_release(inode, filp); |
64ba3dc3 | 2055 | if (retval != -ERESTARTSYS) |
1da177e4 | 2056 | return retval; |
64ba3dc3 AB |
2057 | |
2058 | if (signal_pending(current)) | |
1da177e4 | 2059 | return retval; |
64ba3dc3 | 2060 | |
1da177e4 LT |
2061 | schedule(); |
2062 | /* | |
2063 | * Need to reset f_op in case a hangup happened. | |
2064 | */ | |
2065 | if (filp->f_op == &hung_up_tty_fops) | |
2066 | filp->f_op = &tty_fops; | |
2067 | goto retry_open; | |
2068 | } | |
d4855e1f | 2069 | clear_bit(TTY_HUPPED, &tty->flags); |
89c8d91e | 2070 | tty_unlock(tty); |
eeb89d91 | 2071 | |
24ec839c PZ |
2072 | |
2073 | mutex_lock(&tty_mutex); | |
89c8d91e | 2074 | tty_lock(tty); |
24ec839c | 2075 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2076 | if (!noctty && |
2077 | current->signal->leader && | |
2078 | !current->signal->tty && | |
ab521dc0 | 2079 | tty->session == NULL) |
2a65f1d9 | 2080 | __proc_set_tty(current, tty); |
24ec839c | 2081 | spin_unlock_irq(¤t->sighand->siglock); |
89c8d91e | 2082 | tty_unlock(tty); |
24ec839c | 2083 | mutex_unlock(&tty_mutex); |
1da177e4 | 2084 | return 0; |
ba5db448 | 2085 | err_unlock: |
ba5db448 JS |
2086 | mutex_unlock(&tty_mutex); |
2087 | /* after locks to avoid deadlock */ | |
2088 | if (!IS_ERR_OR_NULL(driver)) | |
2089 | tty_driver_kref_put(driver); | |
2090 | err_file: | |
2091 | tty_free_file(filp); | |
2092 | return retval; | |
1da177e4 LT |
2093 | } |
2094 | ||
39d95b9d JC |
2095 | |
2096 | ||
af9b897e AC |
2097 | /** |
2098 | * tty_poll - check tty status | |
2099 | * @filp: file being polled | |
2100 | * @wait: poll wait structures to update | |
2101 | * | |
2102 | * Call the line discipline polling method to obtain the poll | |
2103 | * status of the device. | |
2104 | * | |
2105 | * Locking: locks called line discipline but ldisc poll method | |
2106 | * may be re-entered freely by other callers. | |
2107 | */ | |
2108 | ||
37bdfb07 | 2109 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2110 | { |
d996b62a | 2111 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2112 | struct tty_ldisc *ld; |
2113 | int ret = 0; | |
2114 | ||
6131ffaa | 2115 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
1da177e4 | 2116 | return 0; |
37bdfb07 | 2117 | |
1da177e4 | 2118 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2119 | if (ld->ops->poll) |
2120 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2121 | tty_ldisc_deref(ld); |
2122 | return ret; | |
2123 | } | |
2124 | ||
ec79d605 | 2125 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2126 | { |
d996b62a | 2127 | struct tty_struct *tty = file_tty(filp); |
f6c8dbe6 | 2128 | struct tty_ldisc *ldisc; |
47f86834 | 2129 | unsigned long flags; |
5d1e3230 | 2130 | int retval = 0; |
1da177e4 | 2131 | |
6131ffaa | 2132 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
5d1e3230 | 2133 | goto out; |
37bdfb07 | 2134 | |
1da177e4 LT |
2135 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2136 | if (retval <= 0) | |
5d1e3230 | 2137 | goto out; |
1da177e4 | 2138 | |
f6c8dbe6 PH |
2139 | ldisc = tty_ldisc_ref(tty); |
2140 | if (ldisc) { | |
2141 | if (ldisc->ops->fasync) | |
2142 | ldisc->ops->fasync(tty, on); | |
2143 | tty_ldisc_deref(ldisc); | |
2144 | } | |
2145 | ||
1da177e4 | 2146 | if (on) { |
ab521dc0 EB |
2147 | enum pid_type type; |
2148 | struct pid *pid; | |
f6c8dbe6 | 2149 | |
47f86834 | 2150 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2151 | if (tty->pgrp) { |
2152 | pid = tty->pgrp; | |
2153 | type = PIDTYPE_PGID; | |
2154 | } else { | |
2155 | pid = task_pid(current); | |
2156 | type = PIDTYPE_PID; | |
2157 | } | |
80e1e823 | 2158 | get_pid(pid); |
70362511 | 2159 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2160 | retval = __f_setown(filp, pid, type, 0); |
2161 | put_pid(pid); | |
1da177e4 | 2162 | } |
5d1e3230 | 2163 | out: |
ec79d605 AB |
2164 | return retval; |
2165 | } | |
2166 | ||
2167 | static int tty_fasync(int fd, struct file *filp, int on) | |
2168 | { | |
89c8d91e | 2169 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2170 | int retval; |
89c8d91e AC |
2171 | |
2172 | tty_lock(tty); | |
ec79d605 | 2173 | retval = __tty_fasync(fd, filp, on); |
89c8d91e AC |
2174 | tty_unlock(tty); |
2175 | ||
5d1e3230 | 2176 | return retval; |
1da177e4 LT |
2177 | } |
2178 | ||
af9b897e AC |
2179 | /** |
2180 | * tiocsti - fake input character | |
2181 | * @tty: tty to fake input into | |
2182 | * @p: pointer to character | |
2183 | * | |
3a4fa0a2 | 2184 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2185 | * input management. |
2186 | * | |
2187 | * FIXME: does not honour flow control ?? | |
2188 | * | |
2189 | * Locking: | |
137084bb | 2190 | * Called functions take tty_ldiscs_lock |
af9b897e | 2191 | * current->signal->tty check is safe without locks |
28298232 AC |
2192 | * |
2193 | * FIXME: may race normal receive processing | |
af9b897e AC |
2194 | */ |
2195 | ||
1da177e4 LT |
2196 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2197 | { | |
2198 | char ch, mbz = 0; | |
2199 | struct tty_ldisc *ld; | |
37bdfb07 | 2200 | |
1da177e4 LT |
2201 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2202 | return -EPERM; | |
2203 | if (get_user(ch, p)) | |
2204 | return -EFAULT; | |
1e641743 | 2205 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2206 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2207 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2208 | tty_ldisc_deref(ld); |
2209 | return 0; | |
2210 | } | |
2211 | ||
af9b897e AC |
2212 | /** |
2213 | * tiocgwinsz - implement window query ioctl | |
2214 | * @tty; tty | |
2215 | * @arg: user buffer for result | |
2216 | * | |
808a0d38 | 2217 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2218 | * |
dee4a0be | 2219 | * Locking: tty->winsize_mutex is taken to ensure the winsize data |
808a0d38 | 2220 | * is consistent. |
af9b897e AC |
2221 | */ |
2222 | ||
37bdfb07 | 2223 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2224 | { |
808a0d38 AC |
2225 | int err; |
2226 | ||
dee4a0be | 2227 | mutex_lock(&tty->winsize_mutex); |
808a0d38 | 2228 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
dee4a0be | 2229 | mutex_unlock(&tty->winsize_mutex); |
808a0d38 AC |
2230 | |
2231 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2232 | } |
2233 | ||
af9b897e | 2234 | /** |
8c9a9dd0 AC |
2235 | * tty_do_resize - resize event |
2236 | * @tty: tty being resized | |
8c9a9dd0 AC |
2237 | * @rows: rows (character) |
2238 | * @cols: cols (character) | |
2239 | * | |
3ad2f3fb | 2240 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2241 | * peform a terminal resize correctly |
af9b897e AC |
2242 | */ |
2243 | ||
fc6f6238 | 2244 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2245 | { |
fc6f6238 | 2246 | struct pid *pgrp; |
47f86834 | 2247 | unsigned long flags; |
1da177e4 | 2248 | |
fc6f6238 | 2249 | /* Lock the tty */ |
dee4a0be | 2250 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 | 2251 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
ca9bda00 | 2252 | goto done; |
47f86834 AC |
2253 | /* Get the PID values and reference them so we can |
2254 | avoid holding the tty ctrl lock while sending signals */ | |
2255 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2256 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2257 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2258 | ||
2259 | if (pgrp) | |
2260 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2261 | put_pid(pgrp); |
47f86834 | 2262 | |
8c9a9dd0 | 2263 | tty->winsize = *ws; |
ca9bda00 | 2264 | done: |
dee4a0be | 2265 | mutex_unlock(&tty->winsize_mutex); |
1da177e4 LT |
2266 | return 0; |
2267 | } | |
4d334fd1 | 2268 | EXPORT_SYMBOL(tty_do_resize); |
1da177e4 | 2269 | |
8c9a9dd0 AC |
2270 | /** |
2271 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2272 | * @tty; tty side of tty |
8c9a9dd0 AC |
2273 | * @arg: user buffer for result |
2274 | * | |
2275 | * Copies the user idea of the window size to the kernel. Traditionally | |
2276 | * this is just advisory information but for the Linux console it | |
2277 | * actually has driver level meaning and triggers a VC resize. | |
2278 | * | |
2279 | * Locking: | |
25985edc | 2280 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2281 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2282 | * then calls into the default method. | |
2283 | */ | |
2284 | ||
fc6f6238 | 2285 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2286 | { |
2287 | struct winsize tmp_ws; | |
2288 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2289 | return -EFAULT; | |
2290 | ||
2291 | if (tty->ops->resize) | |
fc6f6238 | 2292 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2293 | else |
fc6f6238 | 2294 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2295 | } |
2296 | ||
af9b897e AC |
2297 | /** |
2298 | * tioccons - allow admin to move logical console | |
2299 | * @file: the file to become console | |
2300 | * | |
25985edc | 2301 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2302 | * |
2303 | * Locking: uses redirect_lock to guard the redirect information | |
2304 | */ | |
2305 | ||
1da177e4 LT |
2306 | static int tioccons(struct file *file) |
2307 | { | |
2308 | if (!capable(CAP_SYS_ADMIN)) | |
2309 | return -EPERM; | |
2310 | if (file->f_op->write == redirected_tty_write) { | |
2311 | struct file *f; | |
2312 | spin_lock(&redirect_lock); | |
2313 | f = redirect; | |
2314 | redirect = NULL; | |
2315 | spin_unlock(&redirect_lock); | |
2316 | if (f) | |
2317 | fput(f); | |
2318 | return 0; | |
2319 | } | |
2320 | spin_lock(&redirect_lock); | |
2321 | if (redirect) { | |
2322 | spin_unlock(&redirect_lock); | |
2323 | return -EBUSY; | |
2324 | } | |
cb0942b8 | 2325 | redirect = get_file(file); |
1da177e4 LT |
2326 | spin_unlock(&redirect_lock); |
2327 | return 0; | |
2328 | } | |
2329 | ||
af9b897e AC |
2330 | /** |
2331 | * fionbio - non blocking ioctl | |
2332 | * @file: file to set blocking value | |
2333 | * @p: user parameter | |
2334 | * | |
2335 | * Historical tty interfaces had a blocking control ioctl before | |
2336 | * the generic functionality existed. This piece of history is preserved | |
2337 | * in the expected tty API of posix OS's. | |
2338 | * | |
6146b9af | 2339 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2340 | */ |
1da177e4 LT |
2341 | |
2342 | static int fionbio(struct file *file, int __user *p) | |
2343 | { | |
2344 | int nonblock; | |
2345 | ||
2346 | if (get_user(nonblock, p)) | |
2347 | return -EFAULT; | |
2348 | ||
db1dd4d3 | 2349 | spin_lock(&file->f_lock); |
1da177e4 LT |
2350 | if (nonblock) |
2351 | file->f_flags |= O_NONBLOCK; | |
2352 | else | |
2353 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2354 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2355 | return 0; |
2356 | } | |
2357 | ||
af9b897e AC |
2358 | /** |
2359 | * tiocsctty - set controlling tty | |
2360 | * @tty: tty structure | |
2361 | * @arg: user argument | |
2362 | * | |
2363 | * This ioctl is used to manage job control. It permits a session | |
2364 | * leader to set this tty as the controlling tty for the session. | |
2365 | * | |
2366 | * Locking: | |
28298232 | 2367 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2368 | * Takes tasklist_lock internally to walk sessions |
2369 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2370 | */ |
2371 | ||
1da177e4 LT |
2372 | static int tiocsctty(struct tty_struct *tty, int arg) |
2373 | { | |
24ec839c | 2374 | int ret = 0; |
ab521dc0 | 2375 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2376 | return ret; |
2377 | ||
2378 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2379 | /* |
2380 | * The process must be a session leader and | |
2381 | * not have a controlling tty already. | |
2382 | */ | |
24ec839c PZ |
2383 | if (!current->signal->leader || current->signal->tty) { |
2384 | ret = -EPERM; | |
2385 | goto unlock; | |
2386 | } | |
2387 | ||
ab521dc0 | 2388 | if (tty->session) { |
1da177e4 LT |
2389 | /* |
2390 | * This tty is already the controlling | |
2391 | * tty for another session group! | |
2392 | */ | |
37bdfb07 | 2393 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2394 | /* |
2395 | * Steal it away | |
2396 | */ | |
1da177e4 | 2397 | read_lock(&tasklist_lock); |
24ec839c | 2398 | session_clear_tty(tty->session); |
1da177e4 | 2399 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2400 | } else { |
2401 | ret = -EPERM; | |
2402 | goto unlock; | |
2403 | } | |
1da177e4 | 2404 | } |
24ec839c PZ |
2405 | proc_set_tty(current, tty); |
2406 | unlock: | |
28298232 | 2407 | mutex_unlock(&tty_mutex); |
24ec839c | 2408 | return ret; |
1da177e4 LT |
2409 | } |
2410 | ||
5d0fdf1e AC |
2411 | /** |
2412 | * tty_get_pgrp - return a ref counted pgrp pid | |
2413 | * @tty: tty to read | |
2414 | * | |
2415 | * Returns a refcounted instance of the pid struct for the process | |
2416 | * group controlling the tty. | |
2417 | */ | |
2418 | ||
2419 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2420 | { | |
2421 | unsigned long flags; | |
2422 | struct pid *pgrp; | |
2423 | ||
2424 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2425 | pgrp = get_pid(tty->pgrp); | |
2426 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2427 | ||
2428 | return pgrp; | |
2429 | } | |
2430 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2431 | ||
af9b897e AC |
2432 | /** |
2433 | * tiocgpgrp - get process group | |
2434 | * @tty: tty passed by user | |
25985edc | 2435 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2436 | * @p: returned pid |
2437 | * | |
2438 | * Obtain the process group of the tty. If there is no process group | |
2439 | * return an error. | |
2440 | * | |
24ec839c | 2441 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2442 | */ |
2443 | ||
1da177e4 LT |
2444 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2445 | { | |
5d0fdf1e AC |
2446 | struct pid *pid; |
2447 | int ret; | |
1da177e4 LT |
2448 | /* |
2449 | * (tty == real_tty) is a cheap way of | |
2450 | * testing if the tty is NOT a master pty. | |
2451 | */ | |
2452 | if (tty == real_tty && current->signal->tty != real_tty) | |
2453 | return -ENOTTY; | |
5d0fdf1e AC |
2454 | pid = tty_get_pgrp(real_tty); |
2455 | ret = put_user(pid_vnr(pid), p); | |
2456 | put_pid(pid); | |
2457 | return ret; | |
1da177e4 LT |
2458 | } |
2459 | ||
af9b897e AC |
2460 | /** |
2461 | * tiocspgrp - attempt to set process group | |
2462 | * @tty: tty passed by user | |
2463 | * @real_tty: tty side device matching tty passed by user | |
2464 | * @p: pid pointer | |
2465 | * | |
2466 | * Set the process group of the tty to the session passed. Only | |
2467 | * permitted where the tty session is our session. | |
2468 | * | |
47f86834 | 2469 | * Locking: RCU, ctrl lock |
af9b897e AC |
2470 | */ |
2471 | ||
1da177e4 LT |
2472 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2473 | { | |
04a2e6a5 EB |
2474 | struct pid *pgrp; |
2475 | pid_t pgrp_nr; | |
1da177e4 | 2476 | int retval = tty_check_change(real_tty); |
47f86834 | 2477 | unsigned long flags; |
1da177e4 LT |
2478 | |
2479 | if (retval == -EIO) | |
2480 | return -ENOTTY; | |
2481 | if (retval) | |
2482 | return retval; | |
2483 | if (!current->signal->tty || | |
2484 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2485 | (real_tty->session != task_session(current))) |
1da177e4 | 2486 | return -ENOTTY; |
04a2e6a5 | 2487 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2488 | return -EFAULT; |
04a2e6a5 | 2489 | if (pgrp_nr < 0) |
1da177e4 | 2490 | return -EINVAL; |
04a2e6a5 | 2491 | rcu_read_lock(); |
b488893a | 2492 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2493 | retval = -ESRCH; |
2494 | if (!pgrp) | |
2495 | goto out_unlock; | |
2496 | retval = -EPERM; | |
2497 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2498 | goto out_unlock; | |
2499 | retval = 0; | |
47f86834 | 2500 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2501 | put_pid(real_tty->pgrp); |
2502 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2503 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2504 | out_unlock: |
2505 | rcu_read_unlock(); | |
2506 | return retval; | |
1da177e4 LT |
2507 | } |
2508 | ||
af9b897e AC |
2509 | /** |
2510 | * tiocgsid - get session id | |
2511 | * @tty: tty passed by user | |
25985edc | 2512 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2513 | * @p: pointer to returned session id |
2514 | * | |
2515 | * Obtain the session id of the tty. If there is no session | |
2516 | * return an error. | |
2517 | * | |
24ec839c | 2518 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2519 | */ |
2520 | ||
1da177e4 LT |
2521 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2522 | { | |
2523 | /* | |
2524 | * (tty == real_tty) is a cheap way of | |
2525 | * testing if the tty is NOT a master pty. | |
2526 | */ | |
2527 | if (tty == real_tty && current->signal->tty != real_tty) | |
2528 | return -ENOTTY; | |
ab521dc0 | 2529 | if (!real_tty->session) |
1da177e4 | 2530 | return -ENOTTY; |
b488893a | 2531 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2532 | } |
2533 | ||
af9b897e AC |
2534 | /** |
2535 | * tiocsetd - set line discipline | |
2536 | * @tty: tty device | |
2537 | * @p: pointer to user data | |
2538 | * | |
2539 | * Set the line discipline according to user request. | |
2540 | * | |
2541 | * Locking: see tty_set_ldisc, this function is just a helper | |
2542 | */ | |
2543 | ||
1da177e4 LT |
2544 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2545 | { | |
2546 | int ldisc; | |
04f378b1 | 2547 | int ret; |
1da177e4 LT |
2548 | |
2549 | if (get_user(ldisc, p)) | |
2550 | return -EFAULT; | |
04f378b1 | 2551 | |
04f378b1 | 2552 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2553 | |
2554 | return ret; | |
1da177e4 LT |
2555 | } |
2556 | ||
af9b897e AC |
2557 | /** |
2558 | * send_break - performed time break | |
2559 | * @tty: device to break on | |
2560 | * @duration: timeout in mS | |
2561 | * | |
2562 | * Perform a timed break on hardware that lacks its own driver level | |
2563 | * timed break functionality. | |
2564 | * | |
2565 | * Locking: | |
28298232 | 2566 | * atomic_write_lock serializes |
af9b897e | 2567 | * |
af9b897e AC |
2568 | */ |
2569 | ||
b20f3ae5 | 2570 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2571 | { |
9e98966c AC |
2572 | int retval; |
2573 | ||
2574 | if (tty->ops->break_ctl == NULL) | |
2575 | return 0; | |
2576 | ||
2577 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2578 | retval = tty->ops->break_ctl(tty, duration); | |
2579 | else { | |
2580 | /* Do the work ourselves */ | |
2581 | if (tty_write_lock(tty, 0) < 0) | |
2582 | return -EINTR; | |
2583 | retval = tty->ops->break_ctl(tty, -1); | |
2584 | if (retval) | |
2585 | goto out; | |
2586 | if (!signal_pending(current)) | |
2587 | msleep_interruptible(duration); | |
2588 | retval = tty->ops->break_ctl(tty, 0); | |
2589 | out: | |
2590 | tty_write_unlock(tty); | |
2591 | if (signal_pending(current)) | |
2592 | retval = -EINTR; | |
2593 | } | |
2594 | return retval; | |
1da177e4 LT |
2595 | } |
2596 | ||
af9b897e | 2597 | /** |
f34d7a5b | 2598 | * tty_tiocmget - get modem status |
af9b897e AC |
2599 | * @tty: tty device |
2600 | * @file: user file pointer | |
2601 | * @p: pointer to result | |
2602 | * | |
2603 | * Obtain the modem status bits from the tty driver if the feature | |
2604 | * is supported. Return -EINVAL if it is not available. | |
2605 | * | |
2606 | * Locking: none (up to the driver) | |
2607 | */ | |
2608 | ||
60b33c13 | 2609 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2610 | { |
2611 | int retval = -EINVAL; | |
2612 | ||
f34d7a5b | 2613 | if (tty->ops->tiocmget) { |
60b33c13 | 2614 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2615 | |
2616 | if (retval >= 0) | |
2617 | retval = put_user(retval, p); | |
2618 | } | |
2619 | return retval; | |
2620 | } | |
2621 | ||
af9b897e | 2622 | /** |
f34d7a5b | 2623 | * tty_tiocmset - set modem status |
af9b897e | 2624 | * @tty: tty device |
af9b897e AC |
2625 | * @cmd: command - clear bits, set bits or set all |
2626 | * @p: pointer to desired bits | |
2627 | * | |
2628 | * Set the modem status bits from the tty driver if the feature | |
2629 | * is supported. Return -EINVAL if it is not available. | |
2630 | * | |
2631 | * Locking: none (up to the driver) | |
2632 | */ | |
2633 | ||
20b9d177 | 2634 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2635 | unsigned __user *p) |
2636 | { | |
ae677517 AC |
2637 | int retval; |
2638 | unsigned int set, clear, val; | |
1da177e4 | 2639 | |
ae677517 AC |
2640 | if (tty->ops->tiocmset == NULL) |
2641 | return -EINVAL; | |
1da177e4 | 2642 | |
ae677517 AC |
2643 | retval = get_user(val, p); |
2644 | if (retval) | |
2645 | return retval; | |
2646 | set = clear = 0; | |
2647 | switch (cmd) { | |
2648 | case TIOCMBIS: | |
2649 | set = val; | |
2650 | break; | |
2651 | case TIOCMBIC: | |
2652 | clear = val; | |
2653 | break; | |
2654 | case TIOCMSET: | |
2655 | set = val; | |
2656 | clear = ~val; | |
2657 | break; | |
2658 | } | |
2659 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2660 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2661 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2662 | } |
2663 | ||
d281da7f AC |
2664 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2665 | { | |
2666 | int retval = -EINVAL; | |
2667 | struct serial_icounter_struct icount; | |
2668 | memset(&icount, 0, sizeof(icount)); | |
2669 | if (tty->ops->get_icount) | |
2670 | retval = tty->ops->get_icount(tty, &icount); | |
2671 | if (retval != 0) | |
2672 | return retval; | |
2673 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2674 | return -EFAULT; | |
2675 | return 0; | |
2676 | } | |
2677 | ||
e8b70e7d AC |
2678 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2679 | { | |
2680 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2681 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2682 | tty = tty->link; | |
2683 | return tty; | |
2684 | } | |
2685 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2686 | ||
2687 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2688 | { | |
2689 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2690 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2691 | return tty; | |
2692 | return tty->link; | |
2693 | } | |
2694 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2695 | ||
1da177e4 LT |
2696 | /* |
2697 | * Split this up, as gcc can choke on it otherwise.. | |
2698 | */ | |
04f378b1 | 2699 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2700 | { |
d996b62a NP |
2701 | struct tty_struct *tty = file_tty(file); |
2702 | struct tty_struct *real_tty; | |
1da177e4 LT |
2703 | void __user *p = (void __user *)arg; |
2704 | int retval; | |
2705 | struct tty_ldisc *ld; | |
37bdfb07 | 2706 | |
6131ffaa | 2707 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
1da177e4 LT |
2708 | return -EINVAL; |
2709 | ||
e8b70e7d | 2710 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2711 | |
2712 | /* | |
2713 | * Factor out some common prep work | |
2714 | */ | |
2715 | switch (cmd) { | |
2716 | case TIOCSETD: | |
2717 | case TIOCSBRK: | |
2718 | case TIOCCBRK: | |
2719 | case TCSBRK: | |
37bdfb07 | 2720 | case TCSBRKP: |
1da177e4 LT |
2721 | retval = tty_check_change(tty); |
2722 | if (retval) | |
2723 | return retval; | |
2724 | if (cmd != TIOCCBRK) { | |
2725 | tty_wait_until_sent(tty, 0); | |
2726 | if (signal_pending(current)) | |
2727 | return -EINTR; | |
2728 | } | |
2729 | break; | |
2730 | } | |
2731 | ||
9e98966c AC |
2732 | /* |
2733 | * Now do the stuff. | |
2734 | */ | |
1da177e4 | 2735 | switch (cmd) { |
37bdfb07 AC |
2736 | case TIOCSTI: |
2737 | return tiocsti(tty, p); | |
2738 | case TIOCGWINSZ: | |
8f520021 | 2739 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2740 | case TIOCSWINSZ: |
fc6f6238 | 2741 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2742 | case TIOCCONS: |
2743 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2744 | case FIONBIO: | |
2745 | return fionbio(file, p); | |
2746 | case TIOCEXCL: | |
2747 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2748 | return 0; | |
2749 | case TIOCNXCL: | |
2750 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2751 | return 0; | |
84fd7bdf CG |
2752 | case TIOCGEXCL: |
2753 | { | |
2754 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); | |
2755 | return put_user(excl, (int __user *)p); | |
2756 | } | |
37bdfb07 AC |
2757 | case TIOCNOTTY: |
2758 | if (current->signal->tty != tty) | |
2759 | return -ENOTTY; | |
2760 | no_tty(); | |
2761 | return 0; | |
2762 | case TIOCSCTTY: | |
2763 | return tiocsctty(tty, arg); | |
2764 | case TIOCGPGRP: | |
2765 | return tiocgpgrp(tty, real_tty, p); | |
2766 | case TIOCSPGRP: | |
2767 | return tiocspgrp(tty, real_tty, p); | |
2768 | case TIOCGSID: | |
2769 | return tiocgsid(tty, real_tty, p); | |
2770 | case TIOCGETD: | |
c65c9bc3 | 2771 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2772 | case TIOCSETD: |
2773 | return tiocsetd(tty, p); | |
3c95c985 KS |
2774 | case TIOCVHANGUP: |
2775 | if (!capable(CAP_SYS_ADMIN)) | |
2776 | return -EPERM; | |
2777 | tty_vhangup(tty); | |
2778 | return 0; | |
b7b8de08 WF |
2779 | case TIOCGDEV: |
2780 | { | |
2781 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2782 | return put_user(ret, (unsigned int __user *)p); | |
2783 | } | |
37bdfb07 AC |
2784 | /* |
2785 | * Break handling | |
2786 | */ | |
2787 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2788 | if (tty->ops->break_ctl) |
9e98966c | 2789 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2790 | return 0; |
37bdfb07 | 2791 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2792 | if (tty->ops->break_ctl) |
9e98966c | 2793 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2794 | return 0; |
2795 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2796 | /* non-zero arg means wait for all output data | |
2797 | * to be sent (performed above) but don't send break. | |
2798 | * This is used by the tcdrain() termios function. | |
2799 | */ | |
2800 | if (!arg) | |
2801 | return send_break(tty, 250); | |
2802 | return 0; | |
2803 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2804 | return send_break(tty, arg ? arg*100 : 250); | |
2805 | ||
2806 | case TIOCMGET: | |
60b33c13 | 2807 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2808 | case TIOCMSET: |
2809 | case TIOCMBIC: | |
2810 | case TIOCMBIS: | |
20b9d177 | 2811 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2812 | case TIOCGICOUNT: |
2813 | retval = tty_tiocgicount(tty, p); | |
2814 | /* For the moment allow fall through to the old method */ | |
2815 | if (retval != -EINVAL) | |
2816 | return retval; | |
2817 | break; | |
37bdfb07 AC |
2818 | case TCFLSH: |
2819 | switch (arg) { | |
2820 | case TCIFLUSH: | |
2821 | case TCIOFLUSH: | |
2822 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2823 | tty_buffer_flush(tty); | |
c5c34d48 | 2824 | break; |
37bdfb07 AC |
2825 | } |
2826 | break; | |
1da177e4 | 2827 | } |
f34d7a5b | 2828 | if (tty->ops->ioctl) { |
6caa76b7 | 2829 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2830 | if (retval != -ENOIOCTLCMD) |
2831 | return retval; | |
2832 | } | |
2833 | ld = tty_ldisc_ref_wait(tty); | |
2834 | retval = -EINVAL; | |
a352def2 AC |
2835 | if (ld->ops->ioctl) { |
2836 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 | 2837 | if (retval == -ENOIOCTLCMD) |
bbb63c51 | 2838 | retval = -ENOTTY; |
1da177e4 LT |
2839 | } |
2840 | tty_ldisc_deref(ld); | |
2841 | return retval; | |
2842 | } | |
2843 | ||
e10cc1df | 2844 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2845 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2846 | unsigned long arg) |
2847 | { | |
d996b62a | 2848 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2849 | struct tty_ldisc *ld; |
2850 | int retval = -ENOIOCTLCMD; | |
2851 | ||
6131ffaa | 2852 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
e10cc1df PF |
2853 | return -EINVAL; |
2854 | ||
f34d7a5b | 2855 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2856 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2857 | if (retval != -ENOIOCTLCMD) |
2858 | return retval; | |
2859 | } | |
2860 | ||
2861 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2862 | if (ld->ops->compat_ioctl) |
2863 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2864 | else |
2865 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2866 | tty_ldisc_deref(ld); |
2867 | ||
2868 | return retval; | |
2869 | } | |
2870 | #endif | |
1da177e4 | 2871 | |
c3c073f8 AV |
2872 | static int this_tty(const void *t, struct file *file, unsigned fd) |
2873 | { | |
2874 | if (likely(file->f_op->read != tty_read)) | |
2875 | return 0; | |
2876 | return file_tty(file) != t ? 0 : fd + 1; | |
2877 | } | |
2878 | ||
1da177e4 LT |
2879 | /* |
2880 | * This implements the "Secure Attention Key" --- the idea is to | |
2881 | * prevent trojan horses by killing all processes associated with this | |
2882 | * tty when the user hits the "Secure Attention Key". Required for | |
2883 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2884 | * |
1da177e4 LT |
2885 | * This code could be nicer; ideally it should send a HUP, wait a few |
2886 | * seconds, then send a INT, and then a KILL signal. But you then | |
2887 | * have to coordinate with the init process, since all processes associated | |
2888 | * with the current tty must be dead before the new getty is allowed | |
2889 | * to spawn. | |
2890 | * | |
2891 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2892 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2893 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2894 | * | |
2895 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2896 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2897 | */ | |
8b6312f4 | 2898 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2899 | { |
2900 | #ifdef TTY_SOFT_SAK | |
2901 | tty_hangup(tty); | |
2902 | #else | |
652486fb | 2903 | struct task_struct *g, *p; |
ab521dc0 | 2904 | struct pid *session; |
1da177e4 | 2905 | int i; |
37bdfb07 | 2906 | |
1da177e4 LT |
2907 | if (!tty) |
2908 | return; | |
24ec839c | 2909 | session = tty->session; |
37bdfb07 | 2910 | |
b3f13deb | 2911 | tty_ldisc_flush(tty); |
1da177e4 | 2912 | |
f34d7a5b | 2913 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2914 | |
1da177e4 | 2915 | read_lock(&tasklist_lock); |
652486fb | 2916 | /* Kill the entire session */ |
ab521dc0 | 2917 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2918 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2919 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2920 | task_pid_nr(p), p->comm); |
652486fb | 2921 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2922 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2923 | /* Now kill any processes that happen to have the |
2924 | * tty open. | |
2925 | */ | |
2926 | do_each_thread(g, p) { | |
2927 | if (p->signal->tty == tty) { | |
1da177e4 | 2928 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2929 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2930 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2931 | send_sig(SIGKILL, p, 1); |
2932 | continue; | |
2933 | } | |
2934 | task_lock(p); | |
c3c073f8 AV |
2935 | i = iterate_fd(p->files, 0, this_tty, tty); |
2936 | if (i != 0) { | |
2937 | printk(KERN_NOTICE "SAK: killed process %d" | |
2938 | " (%s): fd#%d opened to the tty\n", | |
2939 | task_pid_nr(p), p->comm, i - 1); | |
2940 | force_sig(SIGKILL, p); | |
1da177e4 LT |
2941 | } |
2942 | task_unlock(p); | |
652486fb | 2943 | } while_each_thread(g, p); |
1da177e4 LT |
2944 | read_unlock(&tasklist_lock); |
2945 | #endif | |
2946 | } | |
2947 | ||
8b6312f4 EB |
2948 | static void do_SAK_work(struct work_struct *work) |
2949 | { | |
2950 | struct tty_struct *tty = | |
2951 | container_of(work, struct tty_struct, SAK_work); | |
2952 | __do_SAK(tty); | |
2953 | } | |
2954 | ||
1da177e4 LT |
2955 | /* |
2956 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2957 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2958 | * the values which we write to it will be identical to the values which it | |
2959 | * already has. --akpm | |
2960 | */ | |
2961 | void do_SAK(struct tty_struct *tty) | |
2962 | { | |
2963 | if (!tty) | |
2964 | return; | |
1da177e4 LT |
2965 | schedule_work(&tty->SAK_work); |
2966 | } | |
2967 | ||
2968 | EXPORT_SYMBOL(do_SAK); | |
2969 | ||
6e9430ac | 2970 | static int dev_match_devt(struct device *dev, const void *data) |
30004ac9 | 2971 | { |
6e9430ac | 2972 | const dev_t *devt = data; |
30004ac9 DES |
2973 | return dev->devt == *devt; |
2974 | } | |
2975 | ||
2976 | /* Must put_device() after it's unused! */ | |
2977 | static struct device *tty_get_device(struct tty_struct *tty) | |
2978 | { | |
2979 | dev_t devt = tty_devnum(tty); | |
2980 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2981 | } | |
2982 | ||
2983 | ||
af9b897e | 2984 | /** |
2c964a2f | 2985 | * alloc_tty_struct |
af9b897e | 2986 | * |
2c964a2f | 2987 | * This subroutine allocates and initializes a tty structure. |
af9b897e | 2988 | * |
2c964a2f | 2989 | * Locking: none - tty in question is not exposed at this point |
1da177e4 | 2990 | */ |
af9b897e | 2991 | |
2c964a2f | 2992 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
1da177e4 | 2993 | { |
2c964a2f RV |
2994 | struct tty_struct *tty; |
2995 | ||
2996 | tty = kzalloc(sizeof(*tty), GFP_KERNEL); | |
2997 | if (!tty) | |
2998 | return NULL; | |
2999 | ||
9c9f4ded | 3000 | kref_init(&tty->kref); |
1da177e4 | 3001 | tty->magic = TTY_MAGIC; |
01e1abb2 | 3002 | tty_ldisc_init(tty); |
ab521dc0 EB |
3003 | tty->session = NULL; |
3004 | tty->pgrp = NULL; | |
89c8d91e | 3005 | mutex_init(&tty->legacy_mutex); |
d8c1f929 | 3006 | mutex_init(&tty->throttle_mutex); |
6a1c0680 | 3007 | init_rwsem(&tty->termios_rwsem); |
dee4a0be | 3008 | mutex_init(&tty->winsize_mutex); |
36697529 | 3009 | init_ldsem(&tty->ldisc_sem); |
1da177e4 LT |
3010 | init_waitqueue_head(&tty->write_wait); |
3011 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 3012 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 | 3013 | mutex_init(&tty->atomic_write_lock); |
04f378b1 | 3014 | spin_lock_init(&tty->ctrl_lock); |
f9e053dc | 3015 | spin_lock_init(&tty->flow_lock); |
1da177e4 | 3016 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 3017 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
3018 | |
3019 | tty->driver = driver; | |
3020 | tty->ops = driver->ops; | |
3021 | tty->index = idx; | |
3022 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 3023 | tty->dev = tty_get_device(tty); |
2c964a2f RV |
3024 | |
3025 | return tty; | |
1da177e4 LT |
3026 | } |
3027 | ||
6716671d JS |
3028 | /** |
3029 | * deinitialize_tty_struct | |
3030 | * @tty: tty to deinitialize | |
3031 | * | |
3032 | * This subroutine deinitializes a tty structure that has been newly | |
3033 | * allocated but tty_release cannot be called on that yet. | |
3034 | * | |
3035 | * Locking: none - tty in question must not be exposed at this point | |
3036 | */ | |
3037 | void deinitialize_tty_struct(struct tty_struct *tty) | |
3038 | { | |
3039 | tty_ldisc_deinit(tty); | |
3040 | } | |
3041 | ||
f34d7a5b AC |
3042 | /** |
3043 | * tty_put_char - write one character to a tty | |
3044 | * @tty: tty | |
3045 | * @ch: character | |
3046 | * | |
3047 | * Write one byte to the tty using the provided put_char method | |
3048 | * if present. Returns the number of characters successfully output. | |
3049 | * | |
3050 | * Note: the specific put_char operation in the driver layer may go | |
3051 | * away soon. Don't call it directly, use this method | |
1da177e4 | 3052 | */ |
af9b897e | 3053 | |
f34d7a5b | 3054 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 3055 | { |
f34d7a5b AC |
3056 | if (tty->ops->put_char) |
3057 | return tty->ops->put_char(tty, ch); | |
3058 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3059 | } |
f34d7a5b AC |
3060 | EXPORT_SYMBOL_GPL(tty_put_char); |
3061 | ||
d81ed103 | 3062 | struct class *tty_class; |
1da177e4 | 3063 | |
7e73eca6 JS |
3064 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
3065 | unsigned int index, unsigned int count) | |
3066 | { | |
3067 | /* init here, since reused cdevs cause crashes */ | |
3068 | cdev_init(&driver->cdevs[index], &tty_fops); | |
3069 | driver->cdevs[index].owner = driver->owner; | |
3070 | return cdev_add(&driver->cdevs[index], dev, count); | |
3071 | } | |
3072 | ||
1da177e4 | 3073 | /** |
af9b897e AC |
3074 | * tty_register_device - register a tty device |
3075 | * @driver: the tty driver that describes the tty device | |
3076 | * @index: the index in the tty driver for this tty device | |
3077 | * @device: a struct device that is associated with this tty device. | |
3078 | * This field is optional, if there is no known struct device | |
3079 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3080 | * |
01107d34 GKH |
3081 | * Returns a pointer to the struct device for this tty device |
3082 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3083 | * |
af9b897e AC |
3084 | * This call is required to be made to register an individual tty device |
3085 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3086 | * that bit is not set, this function should not be called by a tty | |
3087 | * driver. | |
3088 | * | |
3089 | * Locking: ?? | |
1da177e4 | 3090 | */ |
af9b897e | 3091 | |
01107d34 GKH |
3092 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3093 | struct device *device) | |
1da177e4 | 3094 | { |
6915c0e4 TH |
3095 | return tty_register_device_attr(driver, index, device, NULL, NULL); |
3096 | } | |
3097 | EXPORT_SYMBOL(tty_register_device); | |
3098 | ||
b1b79916 TH |
3099 | static void tty_device_create_release(struct device *dev) |
3100 | { | |
3101 | pr_debug("device: '%s': %s\n", dev_name(dev), __func__); | |
3102 | kfree(dev); | |
3103 | } | |
3104 | ||
6915c0e4 TH |
3105 | /** |
3106 | * tty_register_device_attr - register a tty device | |
3107 | * @driver: the tty driver that describes the tty device | |
3108 | * @index: the index in the tty driver for this tty device | |
3109 | * @device: a struct device that is associated with this tty device. | |
3110 | * This field is optional, if there is no known struct device | |
3111 | * for this tty device it can be set to NULL safely. | |
3112 | * @drvdata: Driver data to be set to device. | |
3113 | * @attr_grp: Attribute group to be set on device. | |
3114 | * | |
3115 | * Returns a pointer to the struct device for this tty device | |
3116 | * (or ERR_PTR(-EFOO) on error). | |
3117 | * | |
3118 | * This call is required to be made to register an individual tty device | |
3119 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3120 | * that bit is not set, this function should not be called by a tty | |
3121 | * driver. | |
3122 | * | |
3123 | * Locking: ?? | |
3124 | */ | |
3125 | struct device *tty_register_device_attr(struct tty_driver *driver, | |
3126 | unsigned index, struct device *device, | |
3127 | void *drvdata, | |
3128 | const struct attribute_group **attr_grp) | |
3129 | { | |
1da177e4 | 3130 | char name[64]; |
6915c0e4 TH |
3131 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
3132 | struct device *dev = NULL; | |
3133 | int retval = -ENODEV; | |
7e73eca6 | 3134 | bool cdev = false; |
1da177e4 LT |
3135 | |
3136 | if (index >= driver->num) { | |
3137 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3138 | " (%d).\n", index); | |
1cdcb6b4 | 3139 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3140 | } |
3141 | ||
1da177e4 LT |
3142 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3143 | pty_line_name(driver, index, name); | |
3144 | else | |
3145 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3146 | |
7e73eca6 | 3147 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
6915c0e4 TH |
3148 | retval = tty_cdev_add(driver, devt, index, 1); |
3149 | if (retval) | |
3150 | goto error; | |
7e73eca6 JS |
3151 | cdev = true; |
3152 | } | |
3153 | ||
6915c0e4 TH |
3154 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
3155 | if (!dev) { | |
3156 | retval = -ENOMEM; | |
3157 | goto error; | |
3158 | } | |
7e73eca6 | 3159 | |
6915c0e4 TH |
3160 | dev->devt = devt; |
3161 | dev->class = tty_class; | |
3162 | dev->parent = device; | |
b1b79916 | 3163 | dev->release = tty_device_create_release; |
6915c0e4 TH |
3164 | dev_set_name(dev, "%s", name); |
3165 | dev->groups = attr_grp; | |
3166 | dev_set_drvdata(dev, drvdata); | |
3167 | ||
3168 | retval = device_register(dev); | |
3169 | if (retval) | |
3170 | goto error; | |
3171 | ||
3172 | return dev; | |
3173 | ||
3174 | error: | |
3175 | put_device(dev); | |
3176 | if (cdev) | |
3177 | cdev_del(&driver->cdevs[index]); | |
3178 | return ERR_PTR(retval); | |
1da177e4 | 3179 | } |
6915c0e4 | 3180 | EXPORT_SYMBOL_GPL(tty_register_device_attr); |
1da177e4 LT |
3181 | |
3182 | /** | |
af9b897e AC |
3183 | * tty_unregister_device - unregister a tty device |
3184 | * @driver: the tty driver that describes the tty device | |
3185 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3186 | * |
af9b897e AC |
3187 | * If a tty device is registered with a call to tty_register_device() then |
3188 | * this function must be called when the tty device is gone. | |
3189 | * | |
3190 | * Locking: ?? | |
1da177e4 | 3191 | */ |
af9b897e | 3192 | |
1da177e4 LT |
3193 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3194 | { | |
37bdfb07 AC |
3195 | device_destroy(tty_class, |
3196 | MKDEV(driver->major, driver->minor_start) + index); | |
7e73eca6 JS |
3197 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) |
3198 | cdev_del(&driver->cdevs[index]); | |
1da177e4 | 3199 | } |
1da177e4 LT |
3200 | EXPORT_SYMBOL(tty_unregister_device); |
3201 | ||
7f0bc6a6 JS |
3202 | /** |
3203 | * __tty_alloc_driver -- allocate tty driver | |
3204 | * @lines: count of lines this driver can handle at most | |
3205 | * @owner: module which is repsonsible for this driver | |
3206 | * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags | |
3207 | * | |
3208 | * This should not be called directly, some of the provided macros should be | |
3209 | * used instead. Use IS_ERR and friends on @retval. | |
3210 | */ | |
3211 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, | |
3212 | unsigned long flags) | |
1da177e4 LT |
3213 | { |
3214 | struct tty_driver *driver; | |
7e73eca6 | 3215 | unsigned int cdevs = 1; |
16a02081 | 3216 | int err; |
1da177e4 | 3217 | |
0019b408 | 3218 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
7f0bc6a6 JS |
3219 | return ERR_PTR(-EINVAL); |
3220 | ||
506eb99a | 3221 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
7f0bc6a6 JS |
3222 | if (!driver) |
3223 | return ERR_PTR(-ENOMEM); | |
3224 | ||
3225 | kref_init(&driver->kref); | |
3226 | driver->magic = TTY_DRIVER_MAGIC; | |
3227 | driver->num = lines; | |
3228 | driver->owner = owner; | |
3229 | driver->flags = flags; | |
16a02081 JS |
3230 | |
3231 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { | |
3232 | driver->ttys = kcalloc(lines, sizeof(*driver->ttys), | |
3233 | GFP_KERNEL); | |
3234 | driver->termios = kcalloc(lines, sizeof(*driver->termios), | |
3235 | GFP_KERNEL); | |
3236 | if (!driver->ttys || !driver->termios) { | |
3237 | err = -ENOMEM; | |
3238 | goto err_free_all; | |
3239 | } | |
3240 | } | |
3241 | ||
3242 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { | |
3243 | driver->ports = kcalloc(lines, sizeof(*driver->ports), | |
3244 | GFP_KERNEL); | |
3245 | if (!driver->ports) { | |
3246 | err = -ENOMEM; | |
3247 | goto err_free_all; | |
3248 | } | |
7e73eca6 JS |
3249 | cdevs = lines; |
3250 | } | |
3251 | ||
3252 | driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); | |
3253 | if (!driver->cdevs) { | |
3254 | err = -ENOMEM; | |
3255 | goto err_free_all; | |
16a02081 | 3256 | } |
7f0bc6a6 | 3257 | |
1da177e4 | 3258 | return driver; |
16a02081 JS |
3259 | err_free_all: |
3260 | kfree(driver->ports); | |
3261 | kfree(driver->ttys); | |
3262 | kfree(driver->termios); | |
3263 | kfree(driver); | |
3264 | return ERR_PTR(err); | |
1da177e4 | 3265 | } |
7f0bc6a6 | 3266 | EXPORT_SYMBOL(__tty_alloc_driver); |
1da177e4 | 3267 | |
7d7b93c1 | 3268 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3269 | { |
7d7b93c1 AC |
3270 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3271 | int i; | |
3272 | struct ktermios *tp; | |
7d7b93c1 AC |
3273 | |
3274 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3275 | /* | |
3276 | * Free the termios and termios_locked structures because | |
3277 | * we don't want to get memory leaks when modular tty | |
3278 | * drivers are removed from the kernel. | |
3279 | */ | |
3280 | for (i = 0; i < driver->num; i++) { | |
3281 | tp = driver->termios[i]; | |
3282 | if (tp) { | |
3283 | driver->termios[i] = NULL; | |
3284 | kfree(tp); | |
3285 | } | |
7d7b93c1 AC |
3286 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3287 | tty_unregister_device(driver, i); | |
3288 | } | |
7d7b93c1 | 3289 | proc_tty_unregister_driver(driver); |
7e73eca6 JS |
3290 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
3291 | cdev_del(&driver->cdevs[0]); | |
7d7b93c1 | 3292 | } |
7e73eca6 | 3293 | kfree(driver->cdevs); |
04831dc1 | 3294 | kfree(driver->ports); |
16a02081 JS |
3295 | kfree(driver->termios); |
3296 | kfree(driver->ttys); | |
1da177e4 LT |
3297 | kfree(driver); |
3298 | } | |
3299 | ||
7d7b93c1 AC |
3300 | void tty_driver_kref_put(struct tty_driver *driver) |
3301 | { | |
3302 | kref_put(&driver->kref, destruct_tty_driver); | |
3303 | } | |
3304 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3305 | ||
b68e31d0 JD |
3306 | void tty_set_operations(struct tty_driver *driver, |
3307 | const struct tty_operations *op) | |
1da177e4 | 3308 | { |
f34d7a5b AC |
3309 | driver->ops = op; |
3310 | }; | |
7d7b93c1 | 3311 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3312 | |
7d7b93c1 AC |
3313 | void put_tty_driver(struct tty_driver *d) |
3314 | { | |
3315 | tty_driver_kref_put(d); | |
3316 | } | |
1da177e4 | 3317 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3318 | |
3319 | /* | |
3320 | * Called by a tty driver to register itself. | |
3321 | */ | |
3322 | int tty_register_driver(struct tty_driver *driver) | |
3323 | { | |
3324 | int error; | |
37bdfb07 | 3325 | int i; |
1da177e4 | 3326 | dev_t dev; |
b670bde0 | 3327 | struct device *d; |
1da177e4 | 3328 | |
1da177e4 | 3329 | if (!driver->major) { |
37bdfb07 AC |
3330 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3331 | driver->num, driver->name); | |
1da177e4 LT |
3332 | if (!error) { |
3333 | driver->major = MAJOR(dev); | |
3334 | driver->minor_start = MINOR(dev); | |
3335 | } | |
3336 | } else { | |
3337 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3338 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 | 3339 | } |
9bb8a3d4 | 3340 | if (error < 0) |
16a02081 | 3341 | goto err; |
1da177e4 | 3342 | |
7e73eca6 JS |
3343 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
3344 | error = tty_cdev_add(driver, dev, 0, driver->num); | |
3345 | if (error) | |
3346 | goto err_unreg_char; | |
3347 | } | |
1da177e4 | 3348 | |
ca509f69 | 3349 | mutex_lock(&tty_mutex); |
1da177e4 | 3350 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3351 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3352 | |
3353 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3354 | for (i = 0; i < driver->num; i++) { |
3355 | d = tty_register_device(driver, i, NULL); | |
3356 | if (IS_ERR(d)) { | |
3357 | error = PTR_ERR(d); | |
16a02081 | 3358 | goto err_unreg_devs; |
b670bde0 VK |
3359 | } |
3360 | } | |
1da177e4 LT |
3361 | } |
3362 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3363 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3364 | return 0; |
b670bde0 | 3365 | |
16a02081 | 3366 | err_unreg_devs: |
b670bde0 VK |
3367 | for (i--; i >= 0; i--) |
3368 | tty_unregister_device(driver, i); | |
3369 | ||
3370 | mutex_lock(&tty_mutex); | |
3371 | list_del(&driver->tty_drivers); | |
3372 | mutex_unlock(&tty_mutex); | |
3373 | ||
9bb8a3d4 | 3374 | err_unreg_char: |
b670bde0 | 3375 | unregister_chrdev_region(dev, driver->num); |
16a02081 | 3376 | err: |
b670bde0 | 3377 | return error; |
1da177e4 | 3378 | } |
1da177e4 LT |
3379 | EXPORT_SYMBOL(tty_register_driver); |
3380 | ||
3381 | /* | |
3382 | * Called by a tty driver to unregister itself. | |
3383 | */ | |
3384 | int tty_unregister_driver(struct tty_driver *driver) | |
3385 | { | |
7d7b93c1 AC |
3386 | #if 0 |
3387 | /* FIXME */ | |
1da177e4 LT |
3388 | if (driver->refcount) |
3389 | return -EBUSY; | |
7d7b93c1 | 3390 | #endif |
1da177e4 LT |
3391 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3392 | driver->num); | |
ca509f69 | 3393 | mutex_lock(&tty_mutex); |
1da177e4 | 3394 | list_del(&driver->tty_drivers); |
ca509f69 | 3395 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3396 | return 0; |
3397 | } | |
7d7b93c1 | 3398 | |
1da177e4 LT |
3399 | EXPORT_SYMBOL(tty_unregister_driver); |
3400 | ||
24ec839c PZ |
3401 | dev_t tty_devnum(struct tty_struct *tty) |
3402 | { | |
3403 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3404 | } | |
3405 | EXPORT_SYMBOL(tty_devnum); | |
3406 | ||
3407 | void proc_clear_tty(struct task_struct *p) | |
3408 | { | |
7c3b1dcf | 3409 | unsigned long flags; |
9c9f4ded | 3410 | struct tty_struct *tty; |
7c3b1dcf | 3411 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3412 | tty = p->signal->tty; |
24ec839c | 3413 | p->signal->tty = NULL; |
7c3b1dcf | 3414 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3415 | tty_kref_put(tty); |
24ec839c | 3416 | } |
24ec839c | 3417 | |
47f86834 AC |
3418 | /* Called under the sighand lock */ |
3419 | ||
2a65f1d9 | 3420 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3421 | { |
3422 | if (tty) { | |
47f86834 AC |
3423 | unsigned long flags; |
3424 | /* We should not have a session or pgrp to put here but.... */ | |
3425 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3426 | put_pid(tty->session); |
3427 | put_pid(tty->pgrp); | |
ab521dc0 | 3428 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3429 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3430 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3431 | if (tsk->signal->tty) { |
3432 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3433 | tty_kref_put(tsk->signal->tty); | |
3434 | } | |
24ec839c | 3435 | } |
2a65f1d9 | 3436 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3437 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3438 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3439 | } |
3440 | ||
98a27ba4 | 3441 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3442 | { |
3443 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3444 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3445 | spin_unlock_irq(&tsk->sighand->siglock); |
3446 | } | |
3447 | ||
3448 | struct tty_struct *get_current_tty(void) | |
3449 | { | |
3450 | struct tty_struct *tty; | |
934e6ebf AC |
3451 | unsigned long flags; |
3452 | ||
3453 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3454 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3455 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3456 | return tty; |
3457 | } | |
a311f743 | 3458 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3459 | |
d81ed103 AC |
3460 | void tty_default_fops(struct file_operations *fops) |
3461 | { | |
3462 | *fops = tty_fops; | |
3463 | } | |
3464 | ||
1da177e4 LT |
3465 | /* |
3466 | * Initialize the console device. This is called *early*, so | |
3467 | * we can't necessarily depend on lots of kernel help here. | |
3468 | * Just do some early initializations, and do the complex setup | |
3469 | * later. | |
3470 | */ | |
3471 | void __init console_init(void) | |
3472 | { | |
3473 | initcall_t *call; | |
3474 | ||
3475 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3476 | tty_ldisc_begin(); |
1da177e4 LT |
3477 | |
3478 | /* | |
37bdfb07 | 3479 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3480 | * inform about problems etc.. |
3481 | */ | |
1da177e4 LT |
3482 | call = __con_initcall_start; |
3483 | while (call < __con_initcall_end) { | |
3484 | (*call)(); | |
3485 | call++; | |
3486 | } | |
3487 | } | |
3488 | ||
2c9ede55 | 3489 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3490 | { |
3491 | if (!mode) | |
3492 | return NULL; | |
3493 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3494 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3495 | *mode = 0666; | |
3496 | return NULL; | |
3497 | } | |
3498 | ||
1da177e4 LT |
3499 | static int __init tty_class_init(void) |
3500 | { | |
7fe845d1 | 3501 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3502 | if (IS_ERR(tty_class)) |
3503 | return PTR_ERR(tty_class); | |
e454cea2 | 3504 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3505 | return 0; |
3506 | } | |
3507 | ||
3508 | postcore_initcall(tty_class_init); | |
3509 | ||
3510 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3511 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3512 | |
fbc92a34 KS |
3513 | static ssize_t show_cons_active(struct device *dev, |
3514 | struct device_attribute *attr, char *buf) | |
3515 | { | |
3516 | struct console *cs[16]; | |
3517 | int i = 0; | |
3518 | struct console *c; | |
3519 | ssize_t count = 0; | |
3520 | ||
ac751efa | 3521 | console_lock(); |
a2a6a822 | 3522 | for_each_console(c) { |
fbc92a34 KS |
3523 | if (!c->device) |
3524 | continue; | |
3525 | if (!c->write) | |
3526 | continue; | |
3527 | if ((c->flags & CON_ENABLED) == 0) | |
3528 | continue; | |
3529 | cs[i++] = c; | |
3530 | if (i >= ARRAY_SIZE(cs)) | |
3531 | break; | |
3532 | } | |
723abd87 HR |
3533 | while (i--) { |
3534 | int index = cs[i]->index; | |
3535 | struct tty_driver *drv = cs[i]->device(cs[i], &index); | |
3536 | ||
3537 | /* don't resolve tty0 as some programs depend on it */ | |
3538 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) | |
3539 | count += tty_line_name(drv, index, buf + count); | |
3540 | else | |
3541 | count += sprintf(buf + count, "%s%d", | |
3542 | cs[i]->name, cs[i]->index); | |
3543 | ||
3544 | count += sprintf(buf + count, "%c", i ? ' ':'\n'); | |
3545 | } | |
ac751efa | 3546 | console_unlock(); |
fbc92a34 KS |
3547 | |
3548 | return count; | |
3549 | } | |
3550 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3551 | ||
3552 | static struct device *consdev; | |
3553 | ||
3554 | void console_sysfs_notify(void) | |
3555 | { | |
3556 | if (consdev) | |
3557 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3558 | } | |
3559 | ||
1da177e4 LT |
3560 | /* |
3561 | * Ok, now we can initialize the rest of the tty devices and can count | |
3562 | * on memory allocations, interrupts etc.. | |
3563 | */ | |
31d1d48e | 3564 | int __init tty_init(void) |
1da177e4 LT |
3565 | { |
3566 | cdev_init(&tty_cdev, &tty_fops); | |
3567 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3568 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3569 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3570 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3571 | |
3572 | cdev_init(&console_cdev, &console_fops); | |
3573 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3574 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3575 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3576 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3577 | "console"); |
fbc92a34 KS |
3578 | if (IS_ERR(consdev)) |
3579 | consdev = NULL; | |
3580 | else | |
a2a6a822 | 3581 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3582 | |
1da177e4 | 3583 | #ifdef CONFIG_VT |
d81ed103 | 3584 | vty_init(&console_fops); |
1da177e4 LT |
3585 | #endif |
3586 | return 0; | |
3587 | } | |
31d1d48e | 3588 |